[Hercules Jxd Gasoline Engine for Scout Cars]
[From the U.S. Government Publishing Office, www.gpo.gov]

V] \,3 5 '■ 9-{'lob	TM 9_1706
Document
Reserve	WAR DEPARTMENT
TECHNICAL MANUAL
&
ORDNANCE MAINTENANCE
HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS
September 13, 1942
NON-CIRCULATING

TM 9-1706
1
TECHNICAL MANUAL!	WAR DEPARTMENT,
No. 9-1706 J	Washington, September 13, 1942.
ORDNANCE MAINTENANCE
HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS
Paragraphs
Section I.	General__________________________________________ 1
II.	Service maintenance____________________________ 2-4
III.	Technical inspection___________________________ 5-7
IV.	Power plant trouble shooting	and tune-up while
installed____________________________________ 8-9
V.	Clutch_______________________________________ 10-16
VI.	Cooling system (fan and pump)________________ 17-21
VII.	Electrical—generator and regulator__ _______  22-25
VIII.	Electrical—ignition system__________ _	26-31
IX.	Electrical—starting motor____________________ 32-38
X.	Engine (stripped)____________________________ 39-48
XI.	Fuel system___________________________________ 49-55	,
XII.	Lubrication system____________________________56-59
XIII.	Preparing engine for storage__________________60-69
XIV.	Consolidated service data____________________ 70-77
XV.	Special tools and equipment___________________78-82
Page
Appendix. List of references_______________________________ 320
Index_____________________________________-________________ 322
>	Section I
GENERAL
Paragraph
Scope______________________________________________________ 1
1. Scope.—a. General.—This manual is published for the information and guidance of ordnance maintenance personnel, and is one of several maintenance manuals on these vehicles. It contains detailed instructions for removal, disassembly, inspection, maintenance, repair, assembly, and installation of the Hercules JXD gasoline engine and all its accessories for scout car M3A1. These instructions are supplementary to those in the Field and Technical Manuals prepared for the using arms. Additional descriptive matter and illustrations are included to aid in providing a complete working knowledge of the materiel.
6. Vehicle generally.—Information concerning the service maintenance, technical inspection, and lubrication of the entire vehicle will be found in TM 9-705 and 9-1705.
476794° -42-1	1
ORDNANCE MAINTENANCE
TM 9-1706
c.	Power train.—For maintenance information concerning the power train, refer to TM 9-1705.
d.	Chassis and body.—For maintenance information concerning the chassis and body components, refer to TM 9-1709.
e.	Didsel power plant.—For maintenance information concerning the Hercules Diesel engine, model DJXD, and all its accessories, see TM 9-1707.
Section II
SERVICE MAINTENANCE
Paragraph
Objective_____________________________________________________ 2
Scope-------------------------------------------------------   3
Allocation of repair jobs------------------------------------- 4
2.	Objective.—There is a decided difference between the purpose of organizational maintenance and that of service maintenance. Organizational maintenance is performed by the using arms and has for its primary objectives the routine steps in preventive maintenance, together with the care and adjustment of vehicles and their equipment, so that the materiel will be in good operating condition and there will be a minimum of time lost for repairs. Service maintenance by light and heavy maintenance units of the Ordnance Department has for its primary objectives supply, technical inspection, and corrective action and in general all repairs beyond the capacity of the using arms. This work is accomplished either by unit replacement, overhauling, rebuilding, reclaiming, manufacturing, or any other necessary expedients.
3.	Scope.—The scope of maintenance and repairs by maintenance personnel is determined by the amount of time available, weather conditions, cover and concealment, shelter, proximity or exposure to hostile fire, equipment tools and parts available, and skill of the personnel. Since all these factors are variable, no exact system or rules of procedure can be prescribed or followed.
4.	Allocation, of repair jobs.—The operations mentioned below augment those which may be performed by the using arms.
a.	Clutch.
(1)	Clutch assembly--------------Replace, repair, rebuild.
(2)	Clutch housing---------------Replace.
b.	Cooling system.
(1) Fan assembly----------------- Repair.
(2) Fan bushings or bearings_____Replace.
2
TM 9—1706
HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS 4
(3) Radiator___
(4) Water pump
c. Electrical—generator and regulator.
(1)	Circuit breaker______________
(2)	Generator--------------------
(3)	Voltage regulator------------
(4)	Current regulator____________
d. Electrical—ignition system.
(1) Ignition switch--------------
(2) Distributor__________________
e. Electrical—starter.
(1) Starting motor_______________
(2) Starting switch______________
/. Engine.
(1)	Camshaft_____________________
(2)	Connecting rods______________
(3)	Connecting rod bearings______
(4)	Crankshaft___________________
(5)	Cylinder_____________________
(6)	Crankshaft main bearings_____
(7)	Engine_______________________
(8)	Flywheel_____________________
(9)	Pistons______________________
(10)	Piston pins-----------------
(11)	Piston rings________________
(12)	Piston assembly_____________
(13)	Timing gears________________
(14)	Timing gear cover___________
(15)	Valves----------------------
(16)	Valve guides----------------
g.	Fuel system.
(1)	Carburetor___________________
(2)	Fuel pump________:___________
(3)	Fuel tank____________________
(4)	Fuel gage____________________
h.	Lubrication system.
(1)	Internal oil lines___________
(2)	Oil pump_____________________
Repair.
Repair, replace, rebuild.
Adjust or repair.
Repair or rebuild.
Adjust, repair, rebuild.
Adjust, repair, rebuild.
Repair.,
Repair, rebuild.
Repair, rebuild.
Repair.
Replace.
Replace.
Adjust and replace.
Grind, polish, straighten.
Honeboring.
Replace.
Rebuild, replace.
Replace.
Grind and fit.
Fit.
Fit.
Replace.
Replace.
Replace.
Reface, reseat, insert, and replace.
Replace.
Repair and rebuild.
Repair and rebuild.
Repair.
Repair.
Repair, replace.
Repair, replace.
3
TM 9-1706
5—7	ORDNANCE MAINTENANCE
Section III
TECHNICAL INSPECTION
Paragraph
Description___________________________________________________________________ 5
Inspection form_______________________________________________________________ 6
Practical application_________________________________________________________ 7
5.	Description.—Technical inspections are a follow-up and check on organizational maintenance inspections and other maintenance functions. They determine whether the vehicle should be continued in service or withdrawn from operation for overhaul. These inspections are covered in AR 850-15.
6.	Inspection form.—W. D., Q. M. C. Form No. 260 (Technical Inspection Report of Motor Vehicles) is the standard and official form for recording the inspection of all motor vehicles, including combat vehicles of the Ordnance Department. The extent to which use is made of this form or a modification of it depends entirely on the technical ability of available personnel, the time factor, and the test and shop equipment available.
7.	Practical application.—a. External inspection of clutch.— (1) Test foot lever and make sure of proper mounting. Examine return spring for wear or damage.
(2	) Run vehicle to ascertain if clutch is smooth or jerky, or slips in operation.
b.	Cooling system.— (1) Examine radiator and connections for signs of leakage, clogging, or damage.
(2)	Inspect supporting bracket of fan and bushings and bearings.
(3)	Look at water pump and casing for cracks and leaks and make sure gear on shaft is tight and shaft rotates freely.
c.	Generator and regulator.— (1) Examine pulley for looseness.
(2)	Check all shielding conduits and connections.
(3)	Make sure all mounting and fastening screws are tight. Examine armature and brushes.
(4)	Check voltage and correct output of generator.
(5)	Inspect regulator contact points for burning and gap distance, and check tension of armature springs.
(6)	Examine regulator case for cracks.
d.	Ignition system.— (1) Inspect all harness and terminals for damage, wear, and looseness.
(2)	Examine and test ignition switch.
(3)	Look over distributor. Test for loose mounting or loose connection to knob on dash. Remove upper half shield and inspect cap
4
TM 9-1706
HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS 7-8
for cracks. Inspect breaker points and spring, high-tension rotor, and metal inserts in cap for pitting and burning. Try cam for evidence of wear, looseness, or breakage of governor springs.
e.	Starting motor.— (1) Examine all connections and terminals.
(2) Inspect and test starting switch.
(3) Inspect commutator and brushes.
/. Engine.— (1) Check crankcase, block, head, and head gasket for cracks or leaks. See that all bolts are tight.
(2)	Remove cover and examine valve push rods, springs, and valve clearances.
(3)	Run engine and listen for slapping pistons, knock at bearings, or knock due to presence of carbon.
(4)	Check oil pressure for steady and normal reading with engine running.
g.	Fuel system.— (1) Inspect mounting and connections of fuel pump and check its operation. Examine fuel tanks for leaks or damage.
(2)	Examine carburetor and air cleaner. Try all screws. Inspect connections to accelerator and dash.
(3)	Check fuel gage and switch.
h.	Lubrication system.— (1) Check oil pressure at gage.
(2)	Check oil line connections and brackets for tightness.
Section IV
POWER PLANT TROUBLE SHOOTING AND TUNE-UP WHILE INSTALLED
Paragraph
Trouble shooting--------------------------------------------- 8
Tune-up------------------------------------------------------ 9
8. Trouble shooting.
Symptom
a. Engine, skips or misses.
Cause
a. (1) Spark plugs cracked or dirty.
(2)	High-tension wires broken or shorted.
(3)	Distributor cap or rotor broken, damp, or dirty.
(4)	Faulty distributor points, condenser, or coil.
(5)	Valves adjusted too close or badly worn guides.
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TM 9-1706
8	ORDNANCE MAINTENANCE
Symptom	Cause
(6)	Leaking head gasket.
(7)	Cracked valve seat or water jacket.
(8)	Improperly adjusted carburetor.
(9)	Air leak in intake manifold or head.
(10)	Partially plugged gas line.
b. Lack of power in engine. b. (1) Skipping motor.
(2)	Motor out of time.
(3)	Needs carbon removed and valves ground.
(4)	Low or uneven compression.
(5)	Motor overheats.
(6)	Mixture too rich.
(7)	Clutch slips.
(8)	Brakes dragging.
c. Engine vibrates.	c. (1) Motor mountings loose
or badly worn.
(2)	Bad skip in motor.
(3)	Ignition and timing too far advanced.
(4)	Idle adjustment set too rich.
d. Engine overheats.	d. (1) Circulation plugged in
radiator, causing cool spot in core.
(2)	Radiator and block dirty, retarding circulation.
(3)	Ignition late.
(4)	Brakes dragging.
(5)	Clutch slipping.
(6)	Fan belt slipping.
(7)	Thermostat bad.
(8)	Leak or lack of air circulation.
(9)	Radiator fins bent or clogged.
6
TM 9—1706
HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS 8
Symptom
e. Engine knocks.
f. Grinding or scraping noise in engine.
g. Engine uses too much oil.
Cause
e.	(1) Carbon deposit in head.
(2)	Spark advanced too far.
(3)	Automatic spark advance stuck.
(4)	Governor weights stuck or springs weak.
(5)	Loose wristpins.
(6)	Connecting rod out of alinement.
(7)	Loose rod bearings.
(8)	Loose main bearings.
(9)	End play in cam shaft.
(10)	Loose tappets.
(11)	Sticky valve stems.
(12)	Loose spark plugs.
(13)	Flywheel loose.
f.	(1) Generator bearings worn.
(2)	Water pump bearings bad.
(3)	Lower fan pulley sprung or frame sprung so trunnion hits pulley.
(4)	Broken ring or piston.
(5)	Flywheel pan bent or dirt in flywheel pan hitting flywheel.
(6)	Timing chain loose and rubbing case.
(7)	Oil pan nuts in flywheel housing hitting against flywheel.
q. (1) Piston ring gaps lined up.
(2)	Piston rings worn or carbon in ring grooves.
(3)	Vacuum pump diaphragm cracked or porous.
(4)	Rod or main bearing has too much clearance.
(5)	Oil slinger clearance too great or oil slinger oil seal in housing worn out.
(6)	Excessive cylinder wear.
7
TM 9-1706
8-9	ORDNANCE MAINTENANCE
Symptom	Cause
h. Poor gas mileage.	h. (1) Worn-out spark plugs. (2)	Timing late. (3)	Carburetor dirty and out of adjustment. (4)	Motor idles too fast. (5)	Brakes dragging. (6)	Clutch slips. (7)	Erratic driving. (8)	Automatic choke out of adjustment. (9)	Air cleaner dirty or too full of oil. (10)	Automatic heat control frozen closed.
i. Engine fails to start.	i.	(1) Fuel system clogged or fuel supply exhausted. (2)	Defective fuel pump. (3)	Air vent closed.
j. Generator fails to charge.	(4) No spark at spark plugs. j. (1) Drive belt loose. (2) Voltage regulator out of order. (3) Generator not operating properly.
k. Starting motion of vehicle jerky or delayed.	(4) Poor connections in circuit. k. (1) Worn clutch linkage. (2) W o r n or oil - saturated clutch parts—may also be out of adjustment. (3) Play in universal joints.
9.	Tune-up. cl. General. Best results are obtained in an engine tune-up by using a systematic approach rather than a hit-or-miss seal ch. Before a tune-up is attempted an engine compression test should be made. Successful tuning is impossible without a fairly even compression in the cylinders. Make compression test in the following-manner :
(1)	Remove all spark plugs from the engine. Turn ignition switch off and fully open hand throttle.
8
TM 9-1706
HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS 9
(2)	Insert an accurate compression gage in spark plug hole and crank engine a few turns with starting motor, noting highest gage reading. Do this at each cylinder.
(3)	Compression should be the same in each cylinder within 5 pounds.
b. Procedure.—If compression is found to be correct in all cylinders, proceed with the tune-up in the following order:
(1)	Spark plugs.— (u) Spark plugs should be Champion, model J8, type 14MM, or other make of same model and type.
(b)	Clean the plugs thoroughly.
(c)	Inspect closely for cracked porcelain.
(d)	Set electrode gap between 0.025 and 0.028 inch. Use a round feeler gage. Bend side electrode when regapping.
(2)	Battery and ignition cables.— («) Clean both ends of each battery cable thoroughly. See that connections are tight.
(&) Inspect ignition system high- and low-tension cables. Terminal on each end must be clean and tight. If insulation shows evidence of deterioration, cable should be replaced.
(3)	Distributor.— (a) Remove distributor cap and inspect it carefully for cracks and burned posts.
(&) Remove rotor, clean contact point, and make sure spring contacts secondary terminal.
(c) Clean distributor points with a flat point file. Inspect carefully and replace if cleaning does not remove pits and burns. Never use emery cloth to clean points.
(<7) Adjust points with feeler gage to provide 0.018 to 0.020 inch clearance. Be sure that breaker cam is in position to have points fully separated.
(e) Check condenser. A weak condenser usually results in burned breaker points. A good check is the comparison test, replacing the old with a good condenser and observing for contrast in the spark. The spark from a faulty condenser will form an arc or drag between the points.
(/) Check ignition coil with coil tester. Replace weak coil.
(4)	Ignition tuning.—Check ignition timing to be sure that No. 1 cylinder is firing according to flywheel markings. This is done by attaching one end of a neon timing light to No. 1 spark plug and grounding the other end. Run the engine at an idle speed and note whether the neon flashes coincide with the markings on the flywheel. Distributor can be retarded or advanced until neon flashes are perfectly synchronized with the flywheel markings.
9
TM 9-1706
9	ORDNANCE MAINTENANCE
(5)	Valve clearance.— (a) Remove the valve covers and adjust the push rod screw to valve stem clearance to 0.006 inch on both intake and exhaust valves. Be sure engine is thoroughly warmed before adj ustment.
(6)	Make a visual inspection for evidence of cracked valve spring coils or scored valve stems.
(6)	Carburetor.— (a) Remove bottom bowl of air cleaner by loosening winged nut on each side. Clean out all old oil and dirt. Refill to oil level groove with new engine oil and install. Filtering element should never be removed from cleaner.
(b)	Inspect carburetor flange and intake manifold gasket for leaks.
(c)	Check carburetor float level as described in section XI.
(d)	If necessary, adjust idling screw until engine runs evenly and steadily with leanest possible mixture. Engine should be thoroughly warmed before adjusting carburetor.
(e)	Clean carburetor fuel filter.
(7) Fuel pump.— (a) The pressure from the fuel pump is measured with a fuel pump pressure and vacuum gage. Connect adapter tee into fuel pump outlet line and connect gage hose to adapter tee outlet (fig. 193). Normal pressure should be between 2i/2 and 4 pounds. This gage is also used to check the vacuum condition in the vacuum pump. Connect hose to pump inlet. When motor is running, this vacuum should pull from 8 to 10 inches.
(Z») Remove sediment bowl and screen for cleaning.
(
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•'* ’ if f:dtP3r	'■	3 W;
/ I W I Vi^। it i fl 1 I wl W * VSURE PLATE AND I UNIT, ASSEMBLY-LM-CS-4347
SPRING - LM-C-3431
iPIN, ROD-/LM-C-314I
^SPRING-
/LM-C-4346
LEVER-LM-C-3390
ROLLER, NEEDLE-LM-C-3077
PIN. COTTER -
Figure 8.—Clutch pressure plate and lever unit assembly, exploded view.
springs are seated on yokes and that threaded ends of yokes will push through cover when it is compressed.
e. Reconnect cover plate.	Clutch rebuilder.
Spider.
Wrench, adjustable.
%-inch socket speed wrench.
24
Pin. cotter-bfaxicd
BUTTON - LM-C-2085
1PIN, ROD-‘"7 LM-C-3142
iYOKE--~7 LM-C-4344
1NUT-
■“/LM-C-4345
RA PD SQgl
TM 9-1706
HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS 15
PIN, ROD—LM-C-3142
ROLLER, NEEDLE - LM-C-3077	X
«K.
/	Sb,;-.-; '	'	?
LEVER - LM-C-3390
RA PB 8025
Figure 9.—Clutch lever bearing installation.
-Z/\Q l;v ,.. • ■■,<	t I YOKE - i..M-C-4344
\ J"t I
<	\	tl ' SPRING - LM-C-3431
LM-C-3390	\	fc I	/ '
\ v-j4IlJ /
PLATE \ z	I i IlSaMo	i BUTTON-
LM-C-35'94	V»L7	I 1	-*	' LM*C"2085
\ . .-: X 'Kp
/ s
||t.	H’ ’*’**
IX	?
\ 1 \Ji-
SHBEHI^^HHSbEhhEb^HBS Xfek p.9....807n
Figure 10.—Pressure plate lever unit assembly.
25
TM 9-1706
15
ORDNANCE MAINTENANCE
Line up 6 of the 12 cover plate to flywheel cap screw holes with 6 clamp slots on the rebuilder fixture. Put spider on shaft and compress assembly gradually until all threaded ends of yokes have been centered in and protrude through holes in cover plate. Slide 6 clamps in slots of rebuilder fixture and tighten with slight turn of adjustable wrench on clamp screws. Release spider and remove. Install lever nuts, stem end down, and thread on until flush with the threaded ends of yokes.
Figure 11.—Clutch adjustment.
/. Adjust height of levers.	Gage.
%-inch socket speed wrench.
Rebuilder.
Weight.
Set clutch rebuilder adjustment gage at 2i%2 inches and slide it onto rebuilder shaft (fig. 11). Tighten each lever nut until lever just touches gage stop without raising it. After adjusting each lever, turn stop around several times to see if it touches each lever, yet rotates freely. Remove gage and replace with press weight (fig. 12), compressing and releasing lever several times. Remove weight, re-
26
I | GAUGE
PRESS	GAUGE Fl ROTATING STOP
CLAMP ||	jT 1	/ n
TM 9—1706
HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS . 15
place gage, and retest adjustment. If several tests show one lever refuses to adjust, a weak spring is indicated and it must be replaced.
g. Lock cover plate assembly. Chisel.
Hammer.
Punch.
After final adjustment, lock lever adjustment nuts into slots of yoke stems with a blunt chisel and hammer (fig. 12). Should the
Figure 12.—Clutch lever adjusting nut locking.
hacksaw cut on the nut line up with the slot of the stem, make a new lock with punch and hammer at another point on the rim of the nut.
h. Remove assembly from re- Rebuilder.
builder.
Compress clutch assembly, loosen, and remove clamps. Release spider and remove clutch assembly.
Note.—If clutch rebuilder is not available and an arbor press is used, place on press bed plate as described in disassembly and follow steps, .
&z ^^Ub«ggiwf»iW IWIMMk ty ...--^	*
A.	Cap. radiator.	A.	-- * ■!>*- J ,/V \w«A
B.	rube, radiator inlet.	*, '’S> <1®	fWiM NF * v *^5®* V/	.
C.	Clamp, hose.	. Ht| *	"!►♦	’ $	.	«	*|A.	Ml
I>. Hose, radiator inlet.	*	.< *!■ fx«<	v	>”	, ’
E.	Clamp, heater hose.	. ij® « a-J - ’[ j .	I	#	’ f**
F.	Hose, heater inlet.	i	■■ W	' ‘ fW|	S®
G.	Connection, cylinder head	MR	£■■ &&	, W
H.	Valve, shut-off.	. -.. &■ i	I H I ..	P JSJR UC	\ * A	' '" 1
.1. Support, heater hose.	, - ,.S£ St 1.	T	>fa*.	...5^0	x-WW
K. Hose, heater return.	,	* W | | |R|| - I I •• * ■* ■i
I.	. Clamp, heater hose.	;	I fcjgwR^^	1 .r	^,,*C ‘l
.M. Casket, pump to inlet coimee- &	SS	!»WWM|k*^WK U Y *■ --'JF<'
tion.	, •-. S I	’ X	• ^ ;
N. Connection, inlet.	• %' .V.41W 	’<•2	*
It. Tube assembly. radiator to ■kHBK^sV [ ) Fan belts loose.	(Z>) Adjust.
( ■■ ‘ 1 ’ iVw1r fU
fell Hl ts '
djg~ ” ^wllF s	f/
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"■' 1 III *^Sr/
BRACKET, ASS’Y
FAN MOUNTING—J	FAN ASS>Y
BELT, FAN DRIVE
HUB, FAN PULLEY
PULLEY, FAN DRIVING
RA PD 10839
Figure 14.—Fan and belt assembly, installed.
34
TM 9-1706
HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS 19
A.	Bracket assembly, fan mounting.
B.	Washer, jam nut.
C.	Spindle, fan pulley.
D.	Nut, jam, fan adjusting.
jg fNut, adjusting screw lock.
’ (Washer, lock.
F. Screw, fan adjusting.
G. Wire, lock retainer.
H. Retainer, roller bearing.
J- /ya®herl Grease retaining. [Gasket J
K.	Bearing, roller, fan hub, rear.
L.	Hub, fan pulley.
M.	Blade assembly.
N.	Plug, pipe, lubricating.
P. Gasket.
(Screw, cap.
^[Washer, lock.
R. Bearing, roller, fan hub, front.
S. Washer, roller bearing retaining.
T J^iit, slotted 1 ROner bearing retainer ’ [Pin, cotter J washer.
U. Washer, cork, grease retaining.
V. Washer, spindle retaining.
0
0
0
RA PD 10837
Figure 15.—-Fan, w/bracket assembly.
35
TM 9-1706
19
ORDNANCE MAINTENANCE
(2)	Remove screws from fem %-inch open end wrench. bracket.
Remove two cap screws and lock washers that attach fan bracket to timing gear case (fig- 17).
(3)	Remove fan belts.	None.
Slide belts off fan drive pulley, generator pulley, and fan pulley and remove belts by lifting them up and out over fan blades.
(4)	Remove fan assembly and None.
bracket.
Push fan assembly back against cylinder block and tilt up blade end to clear radiator shroud. Then lift out fan assembly and bracket (fig.
d.	Fan disassembly (fig. 19).—Tools:
1%6'inch open end wrench. 1%6-inch open end wrench. %-inch open end wrench. f/2-inch open end wrench.
(1)	Remo re fan assembly from bracket.
Soft metal drift.
Hammer.
Screw driver.
Pliers.
1 Ci6-inch open end wrench.
Remove fan nut, plain washer, and shakeproof washer and pull fan assembly from bracket. Then take washer off spindle.
(2)	Remove blade assembly 1^-inch open end wrench. from fan pulley hub.
Remove four cap screws and lock washers that attach fan to hub and lift blade assembly from hub. Gasket is shellacked to fan blade assembly.
(3)	Remove bearing retainer Screw driver. lock wire.
Pry out, bearing retainer lock wire from groove in fan hub.
(4)	Remove front and fan spin- 1%6-inch open end wrench. die bearing retaining nut.	Pliers.
Pull cotter pin and remove nut and washer from fan hub spindle.
(5)	Remove front fan roller Soft metal drift.
bearing f rom spindle.	Hammer.
Drive spindle from front roller bearing and remove bearing cone assembly from fan hub.
36
TM 9-1706
HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS 19
Figure 16. -Loosening fan belts.
Figure 17.—Fan mounting bracket removal.
37
|RA PD 1C891
Rpd
TM 9-1706
19
ORDNANCE MAINTENANCE
(6) Remove rear roller bearing Soft metal drift.
from spindle.
Slide retainer, cork washer, and washer from spindle, in order named, and then drive rear bearing cone assembly from spindle.
Figure 18.—Fan and bracket removal.
(7) Remove front and rear roller bearing cups from fan hub.
Soft metal drift.
Hammer.
Drive out front bearing cup and rear bearing cup from fan hub.
38
RA PD 10834
TM 9-1706
HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS 19
D	K
. E	W	»
6	i	11 #
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c	& 39E
RA PD 10840
A.	Nut, jam, fan adjusting.	G. Bracket assembly, fan mount- N. Washer, bearing retaining.	V. Nut, slotted, roller bearing re-
B.	Washer, shakeproof.	ing.	P. Gasket, roller bearing.	taining washer.
C.	Washer, jam nut.	H. Washer, spindle retaining.	Q. Bearing, roller, fan pulley.	W. Pin, cotter, bearing retaining
D.	Screw, fan adjusting.	J.	Spindle, fan pulley.	R.	Hub, fan pulley.	nut.
E.	Nut, adjusting screw lock.	K. Wire, lock, retainer.	S.	Bearing, roller, fan hub	front.	X.	Washer,	lock,	blade	attaching
F.	Washer, lock, adjusting screw L. Retainer, roller bearing.	T.	Blade assembly.	nut.
nut.	M.	Washer, cork grease retaining. U.	Washer, roller bearing	retain-	Y.	Screw, cap, blade	attaching.
ing.
Figure 19.—Fan, with bracket assembly, exploded view.
39
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19	ORDNANCE MAINTENANCE
e.	Maintenance.— (1) Inspect roller bearing and retainers for wear and evidence of pitting. Inspect fan spindle threads for damage or evidence of stripping. Fan roller bearings, retainers, oil seal, and bearing retaining lock wire should be replaced, if these parts are scored or fractured and show excessive wear.
(2)	Should fan spindle threads and nuts show evidence of stripping, spindle must be replaced.
(3)	If threads have become burred during disassembly, run proper size die over spindle threads and use new nuts.
(4)	Fan blades that have bent will throw fan out of balance. A fan with bent blades should be replaced, unless extreme care is taken in bending blades back into proper position.
(5)	Inspect fan belts and replace belts that are frayed, cracked, or saturated with oil.
(6)	Belts that are worn to the extent that they bottom on the pulley V should be replaced. When replacing belts always replace both belts, as dual pullers are used and one adjustment tightens both belts.
(7)	To adjust fan belts, loosen fan spindle jam nut and adjusting screw lock nuts. Then, to tighten belt tension, turn adjusting screw handle to the left. Adjust belts so that there is between % and % inch lateral movement of the belts halfway between the pulleys. With the dual V-belts, very little tension is required to drive the fan and generator. Belts that are adjusted too tightly will cause excessive wear and overheating of the fan roller bearing. After adjustments have been made, carefully check alinement of fan pulley with drive pulley. Misalinement will cause belts to ride up on the pulley flange, causing damage to the belts.
(8)	Care should be taken not to mar the fan roller bearings when removing and replacing. If an arbor press is available it should be used in preference to a soft metal drift when removing and replacing bearings, bearing cups, and spindle from the fan hub.
(«) It is not necessary to remove the bearing cone cups from the fan hub unless they are to be replaced, as they may be cleaned without removing.
(5) In disassembly, before removing fan from hub, mark hub and fan flange so that they will be reassembled in the same position. This is essential because they are balanced as an assembly.
(9)	Before bearing cones are installed in the fan, hub bearings and cups should be packed with lubricant, gear, universal, seasonal grade. Fan bearings are lubricated by removing the plug in the fan hub and
40
TM 9-1706
HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS 19
injecting a small quantity of lubricant every 1,000 miles and 21). See lubrication chart, TM 9-1705.
f. Fan assembly (fig. 19).—Tools:
li/16-inch open end wrench. i%6-inch open end wrench. %-inch open end wrench. %-inch open end wrench.
(1) Replace roller bearing cups.
Soft metal drift. Hammer. Screw driver. Pliers. Hammer.
Soft metal drift.
(figs. 20
Insert front and rear bearing cups in fan hub and drive them in until they bottom against shoulder. Pack bearing cups and bearings with grease and place bearings in cups.
Figure 20.—Removing fan hub grease retaining plug.
(2) Replace rear roller bearing None. retainers.
In order named, install gasket, plain washer, and retainer in fan hub, back of the rear bearing.
41
; RA PD 10892
TM 9-1706
19
ORDNANCE MAINTENANCE
(3) Replace, washer retainer Pliers.
lock wire.	Screw driver.
Secure oil seal washer retainer lock wire in fan hub recess.
(4) Install fan and spindle. Soft metal drift.
Hammer.
]%G-inch open end wrench.
Figure 21.—Inserting pressure grease fitting in fan hub.
Insert spindle in fan hub and replace washer, castle nut, and cotter pin. Tighten this nut to give a loose fit with no end play and lock this adjustment with the cotter pin.
(5) Install fan blade assembly, ^-inch open end wrench.
Place fan blade assembly with gasket on fan hub and install fan cap screws and lock washers.
42
RA PD 10893
TM 9-1706
HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS 19-20
(6) Install fan and hub assent- i^-inch open end wrench.
Insert fan and hub assembly into slot in mounting bracket and replace plain washer and shakeproof washer and jam nut. Do not tighten jam nut, as adjustment will be made when assembly is installed.
(7) Install fan adjusting screw, %-inch open end wrench.
Install fan adjusting screw with lock nut in top bracket and thread screw into spindle.
g. Installation.—Tools: iy16-inch open end wrench. %-inch open end wrench.
(1)	Replace fan belt.	None.
With fan-mounting bracket resting on timing gear case, tilt fan down and slip belts over fan blades and onto drive pulley, fan pulley, and generator pulley (fig. 22).
Make	Type	Manufacturer’s No.	White No.	Ordnance No.	Weight
Hercules		Impeller		HM-40170-CS	WI-316816	C65948	—
(2)	Replace and line up fan- %-inch open end wrench. mounting bracket.
Slide mounting bracket into position on timing gear case pad and insert two attaching cap screws with lock washers. Adjust bracket so that fan pulley is lined up with fan driving pulley and then tighten cap screws.
(3)	Adjust fan belts.	l%6-inch open end wrench.
%-inch open end wrench.
Screw down fan adjusting screw until there is approximately % inch movement of fan belts and tighten lock nut. Check to make sure that fan pulleys are properly alined. If misalinement is visible, loosen cap screw and shift bracket to correct position.
20. Water pump.—a. Description (fig. 23).—The centrifugal type water pump is located at the left front of the engine block and is bolted on the rear of the timing gear case.
(1) Construction (fig. 24).—The water pump shaft is supported on two bushings, a large diameter bushing in the pump cover casting, just
43
TM 9-1706
20
ORDNANCE MAINTENANCE
to the rear of the drive gear, and a bushing of smaller diameter at the extreme rear of the pump body. The front bushing is lubricated by oil from the timing gears and the rear bearing by a grease cup threaded on the end of the body casting. Split ring type packing is used so that the pump can be repacked without disassembling. The impeller and distributor drive gear are keyed and pinned on the pump shaft. A bearing on the pump cover is used for mounting the engine ignition distributor.
Figure 22.—Installing fan belt.
(2) Functioning.—The water pump drive gear is driven from the engine camshaft gear by means of an idler gear which rotates the pump shaft at one-half engine speed. Water is drawn from the bottom of the radiator by the rotation of the pump impeller and is forced to circulate through the engine water jackets and cylinder head, returning through the upper hose into the radiator. When the car heater is in use, return water from the heater enters the pump inlet below.
44

TM 9-1706
HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS 20
A	B C O E
■'"■L"	. v- X
' »•*/: W-'	•
F	N M L	K	J	RA PD 10894
Figure 23.—Water pump assembly, installed.
.?Sil8

a
 ______________________ g CO
RING-HM-22I68A------- Mr,Trr.acccr/iqi c uhtu
GEAR-HM-2236A------- -------------------------------N0TE AS CLEARANCE
KEY.W00DRUFF-BGAX4D-	//	----^CLEARANCE	g
(-GEAR-HM-22I95B	L/J---------------GASKET-HM-22I64A
Z/ ----, , , ,-----PIN-HM-I4507A
-----KEY-W00DRUFF-BGAX6B
JX	X 0	--IMPELLER-HM-40I65A
—n NUSSJ—__________________________XcTr-----—b.ushing-hm-40I68a
/Z/Z/ttM	-----------X	--z---SHAFT-HM-40I72B	g
V	/ pCUP,GREASE-CLEX2B	g
JmT-----ft I
H3> ;i	"mJ ■§	«
M3	J	£
yZ;/^.ISLv\v\K
----Mx'	XlfZ	/	/	ORDNANCE N°-C65948 X BUSHING-HM-22I75A-1	Vpyl	/	/	WHITE N°-3I68I6	M
X] PACKING-HM-22I66A—	A
L BUSHING-HM-22I7IB
U WASHER-HM-4024A	--------KZIT-J/I
---KEY.W00DRUFF-BGAX3CC	RA pD 3350
Figure 24.—Water pump assembly, sectionalized.
46
TM 9-1706
HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS 20
(3) Specifications.
b. Trouble shooting.
Symptoms and probable cause
(1) Loss of cooling water.
(a) Defective hose.
(&) Loose hose connection.
(c) Defective pump packing seal.
() Tighten connections.
(c) Replace packing.
(tZ) Replace shaft.
(a) Refill system.
(Z>) Check drive shaft bearings and impeller. Repair or replace pump. «
Scriber.
Screw driver.
Pliers.
Soft metal hammer.
Pliers.
Open drain cock at lower left-hand radiator hose connection.
(2)	Remove distributor from Screw driver. water pump.
Loosen spark control wire clamping screw and remove wire. Remove distributor advance screw with two plain washers and spring washer and carefully lift distributor from its bearing so as not to move distributor shaft (fig. 25).
(3)	Mark distributor shaft tim-	Straightedge.
ing position.	Scriber.
Holding distributor, place a straightedge on shaft bearing in line over drive gear retaining pin and scribe a line on the pin and bearing which will indicate position of gear when distributor is installed (fig- 26).
(4)	Disconnect pump inlet and Screw driver. car heater hose.
Disconnect pump hose clamp and car heater hose clamp at water pump inlet elbow and slide hose from pipes.
47
TM 9-1706
20
ORDNANCE MAINTENANCE
(5) Remove pump attaching %6-inch open end wrench. screws.	%-inch open end wrench.
Remove four cap screws and lock washers from water discharge inlet pipe. Then remove three cap screws and lock washers holding pump assembly to rear of gear housing (fig. 27).
Figure 25.- Removal of distributor assembly.
48
^APD 10832
TM 9-1706
HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS 20
(6) Remove pump assembly. Soft metal hammer.
Pull water pump back until gear is clear of timing gear housing and lift out water pump assembly (fig. 28). Then take off pump gasket and elbow gasket. It may be necessary to tap pump lightly with a brass hammer to free sleeve mounting from gear case before pump can be pulled out.
Figure 26.—Indicating distributor timing position.
d. Water pump disassembly (fig. 29).—Tools:
Screw7 driver.	Arbor press.
i^-inch open end wrench.	Pliers.
Hammer.	- Spanner wrench.
Punch.	Wooden mallet.
Vise.	%6-inch open end wrench.
(1) Remove discharge pipe and	Screw’ driver.
hose assembly from pump.
Loosen hose clamp at pump outlet connection and pull off hose and discharge pipe assembly.
476794° 42------4
49

TM 9-1706
20
ORDNANCE MAINTENANCE
(2)	Remove water pump cover 1^-inch open end wrench. assembly.
Punch-mark pump body and cover beside one of the screws to prevent reassembling pump body in the wrong position. Then remove four cap screws and lock washers from pump cover flange and separate pump cover assembly from pump body assembly, releasing gasket.
SCREW, CAP — BCAXICF
WASHER, LOCK ~ BECXIK	ra rd
SCREW, CAP - BCAXICC PUMP, WATER, ASSEMBLY - SCREW, CAP - BCAXIEC WASHER, LOCK - BECXIK	HM-40170-CS SCREW, CAP - HM-4625A
/	/	WASHER, LOCK - BECXIM
Figure 27.—Water pump assembly removal.

(3)	Remove water pump impel- Hammer.
ler retaining pin.	Punch.
Vise.
Clamp impeller shaft in a vise and drive out impeller retaining pin.
(4)	Remove water pump im- Arbor press.
peller from shaft.
Place pump cover and shaft under an arbor press and pass shaft out of impeller about y2 inch. Then place a steel supporting block between impeller and cover, and press shaft out of impeller.
50
TM 9-1706
HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS 20
(5)	Remove shaft and gear as- Pliers.
sembly from pump cover.
Remove impeller Woodruff key from shaft, slide shaft out through front of cover, and remove thrust washer from shaft.
(6)	Remove pump packings Spanner wrench.
from cover bushing.
Remove pump packing nut from bushing and take out packing gland and four packings.
PLUG, PIPE - HDLSS-HM-61A	HOSE ~ HM-40064A
CLAMP - CMAX2A
\ pipe—
PUMP, WATER, ASSEMBLY-	....._	\	HM-40690B
HM-40170-CS	/	\
/	:	■ W	CUP, GREASE -
GASKET-WI-A1949X	CLEX2B
CONNECTION, HOSE - HM-44552B
RA PP 8M4
Figure 28.—Water pump assembly, dismounted.
(7)	Remove grease retainers Pliers.
from pump shaft bearings.
Pull out washer retainer and apply grease, water pump, to retaining washer from pump shaft bearing at front of water pump cover.
(8)	Remove distributor drive Wooden mallet.
gear from pump shaft.	Pliers.
Drive pump shaft out of distributor drive gear by holding gear and tapping end of shaft with mallet. After gear is removed, pull Woodruff key from shaft.
51
TM 9-1706
20
ORDNANCE MAINTENANCE
(9)	Remove water pump drive Arbor press.
gear from shaft.
Press long end of pump shaft through drive gear and remove Woodruff key from shaft.
(10)	Remove shaft bearing %6-inch open end wrench.
grease cup.
Remove grease cup located on back of water pump body.
e.	Maintenance.— (1) Clean and inspect all water pump parts before impeller is removed.
(2)	Check shaft for end play, bushings for wear, and gear teeth for fracture or wear. Bushings, gears, and shafts that show signs of wear to the extent of causing the pump to become noisy or inoperative should be replaced.
(3)	Packing ring seals, if broken or brittle, should be replaced with new seals.
(4)	When reassembling pump, use new gaskets on attaching flange and between cover and body.
(5)	It is not necessary to remove the inlet elbow, which is attached to the pump body by twTo cap screws, unless the body casting has been damaged.
(6)	Pack shaft bearing grease cup with grease, water pump, after installation.
f.	Water pump assembly (fig. 29).—Tools:
14-inch open end wrench. %6-inch open end wrench. Arbor press.
Spanner wrench.
(1)	Install bearing grease cup.
Punch.
Hammer.
Screw driver.
%6-inch open end wrench.
Install pump bearing grease cup in rear of pump body.
(2)	Install water pump drive Arbor press.
gear.
Insert Woodruff key in pump shaft. Slide gear down shaft until gear keyway engages key, and press on.
(3)	Install distributor drive Arbor press.
gear on shaft.
Insert Woodruff key in water pump shaft. Slide gear down shaft so keyway in gear engages key, and press on; then insert gear retaining snap ring.
52
TM 9-1706
HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS 20
12	3	7	13
0' ' V- Aft-
/ <■ VI
s /	\	\ I
6	1 \ f \ I
io n 8	9	12	14	15	16
\ A
if tSCS	■*”■“>
1.	Gear—HM-22195B.	9. Washer, lock—BECXIH.
2.	Gear—HM-22336A.	10.	Nut—HM-22177A.
3.	Shaft—HM-40172B.	11.	Gland—HM-21265A.
4.	Key—BGAX6B.	12.	Packing—HM-22166A.
5.	Washer—HM-4024A.	13.	Impeller—HM-40165A.
6.	Gasket—HM-22149A.	14.	Pin—HM-14507A.
7.	Cover assembly—HM-40171CS.	15.	Gasket—HM—22164A.
8.	Screw, cap—BCAXIBA.	16. Body assembly—HM-45735CS.
Figure 29.—Water pump assembly, exploded view.
53
TM 9-1706
20	ORDNANCE MAINTENANCE
(4)	Install grease retaining	None.
washer and retainer in pump cover.
Insert pump grease retaining washer and press retainer into position over washer.
(5)	Install packings in pump None. cover bushings.
Place four packings and packing gland in pump cover bushing. Then screw packing gland nut on, hand tight.
(6)	Install pump shaft and Spanner wrench. gear assembly in cover.
Place thrust washer onto shaft against drive gear and install shaft assembly in pump cover. Then tighten shaft packing gland nut.
(7)	Install impeller on pump Arbor press.
shaft.	Hammer.
Insert Woodruff key in pump shaft. Place impeller on end of shaft so keyway in impeller engages, and press on. Then insert and drive home impeller retaining pin.
(8)	Install pump cover as- ^-inch open end wrench. sembly.
Position gasket on pump body flange and place pump cover assembly on body, lining up punch-marks on body and cover. Then replace four attaching cap screws and lock washers.
(9)	Connect discharge pipe and Screw driver. hose to pwmp.
Slide elbow hose on water pump body outlet pipe and tighten hose clamp.
(10)	Precautions.—In replacing distributor drive gear make sure that hub side of gear is toward shaft bearing shoulder. In assembling pump packing, place flanged end of packing gland into packing nut. Pump packing gland nut should never be tightened with any considerable force.
(11)	Inspection and tests.—After water pump has been reassembled, spin gear shaft to make sure there is no binding due to tightness of packing gland nut.
(12)	Adjustments.—When connecting spark control wire to distributor control arm, clamp wire with control knob on instrument panel
54
TM 9-1706
HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS 20-21
all the way in (down position), and distributor control arm all the way forward (advance position).
g- Wat er pump installation.—Tools:
3/i-inch open end wrench. Screw driver.
%6-inch open end wrench.
(1)	Replace water pump as-	%6-inch open end wrench.
sembly and discharge pipe.	%-inch open end wrench.
Place water pump assembly in position so that pump drive gear meshes with idler gear in gear case. Use new gasket between pump assembly and gear housing and between discharge pipe and block. Secure assembly between gear housing and block, with lock washers and cap screws.
(2)	Connect radiator outlet hose	Screwdriver.
and car heater hose to pump inlet elbow.
Slide radiator hose on elbow and heater hose on pipe elbow. Then tighten hose clamps.
(3)	Install distributor on pump None. cover.
Make sure that scribed lines on distributor bearing and on drive gear retaining pin are in line, and slide distributor in mounting bearing on pump cover so that slot in distributor advance arm is over arm retaining screw lug.
(4)	Connect spark control wire Screw driver. and' secure distributor.
Insert spark control wire in swivel hole on advance arm and tighten clamping screw. Then replace distributor arm advance control retaining screw with one shakeproof and two plain washers.
Note.—If the engine is rotated for the disassembly of other parts, or for any other reason during the time that the water pump and distributor are removed from the engine, the ignition will have to be retimed (see par. 29e(5)).
(5)	Inspect for leaks.—After the water pump has been installed and water replaced in the cooling system, run the engine at idling speed. Inspect hose connections, flanges, and packing gland nut for water leaks. Inspect the shaft where it comes through the pump cover and the oil line connections at the engine block elbow flange for oil leaks.
21.	Radiator.—Information concerning the radiator can be found in TM 9-1709.
55
TM 9-1706
22-23
ORDNANCE MAINTENANCE
Section VII
ELECTRICAL—GENERATOR AND REGULATOR
Paragraph
Description	of	circuit._______________________________________________  22
Trouble shooting	for	circuit_____________________________________________ 23
Generator____________________________________________________________     24
Regulator________________________________________________________________ 25
22.	Description of circuit (fig. 30).—The generator is a 12-volt, 4-brush, 4-pole heavy duty machine, supported on the left side of the engine about level with the top at the front. It is driven by V-belts from the crank shaft. The regulator consists of a cut-out relay, a voltage regulating coil, and a current regulating coil, each controlling a pair of contacts. The regulator is in the circuit between the battery and the generator and automatically keeps the voltage and current delivered by the generator within rated limits. This regulator is mounted in front of the dash, at the left, under the hood of the engine, and is inclosed in a metal casing.
23.	Trouble shooting for circuit.
Symptom and probable cause
a.	Low or no generator output.
(1)	Dry battery.
(2)	Poor battery condition.
(3)	Fully charged battery.
(4)	Loose or dirty connections.
(5)	Burned contacts on regulator units.
(6)	Grounded armature wires or terminal posts.
b.	High generator output.
Short circuit between field and output circuits.
c.	High discharge on ammeter.
Regulator circuit breaker closed.
Probable remedy
(1)	Refill cells.
(2)	Replace battery.
(3)	None (check output when battery is slightly discharged).
(4)	Clean and tighten.
(5)	Clean or replace contacts (check generator field condition).
(6)	Replace wires, insulate terminals.
If necessary, replace field windings. Check regulator contacts.
Repair and adjust circuit breaker. Check generator for damage.
d. Quick checks to determine if units are operating properly.—The following checks can be made to determine whether or not units are operating normally. If not, the checks will indicate whether the generator or regulator is at fault so that the proper corrective steps can be taken.
(1)	Fully charged battery and low charging rate.—This condition indicates normal voltage regulation. To check further, disconnect the
56
TM 9-1706
HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS 23
57
Figure 30.—Generator and regulator, installed.
Ha..PD.TOpO
TM 9-1706
23	ORDNANCE MAINTENANCE
battery wire from the battery (BAT) terminal of the regulator. Connect the positive lead of an ammeter to the battery wire. With the ignition switch in the “off” position, step on the starting switch and crank the engine for about 15 seconds; then start the engine. While it is running at medium speed turn on the lights and any other electrical accessories used on the car and note quickly the generator output, which should be very nearly (not exceed) the value at which the current regulator is set. Then turn off all electrical accessories (lights, etc.) that were on and allow the engine to continue running. As soon as the generator has replaced in the battery the current used in cranking, the voltage regulator, if operating properly, will taper the output down to a few amperes.
(2)	Fully charged battery and high charging rate.—This condition indicates malfunctioning of generator or regulator. Disconnect the field wire from the field (F) terminal of the regulator. This opens the field circuit and the output should immediately drop off to a very few amperes. If it does not, it is an indication that a short circuit exists between the field circuit and output circuit somewhere ahead of the regulator, probably in the generator itself. If the output drops off with the field circuit disconnected at the regulator the trouble is isolated in the regulator. Remove and check the regulator.
(3)	Low battery and low or no charging rate.—This may be caused by a number of conditions. Check the field and output circuits for loose connections. Check for corroded battery terminals, loose or corroded ground strap, and frayed or damaged wires. The high resistance resulting from these conditions will prevent the norma] charge from reaching the battery. If the entire charging circuit is in good condition, either the regulator or generator is at fault.
(a) Connect a jumper wire from the field (F) terminal of the regulator to the generator (GEN) terminal of the regulator. This short-circuits the regulator and should cause the generator output to increase quickly as the engine speed is increased to a medium speed. (Care must be taken to avoid excessive engine speed, as this may cause the generator greatly to exceed its maximum output rating.) If the output does increase, the generator may be assumed to be in operating condition and the cause of the low charging rate would be in the regulator. To find it, the regulator would have to be removed and checked.
(&) If, however, the generator output remains at a few amperes when the field circuit is short-circuited to the generator circuit as described above, then the low output would be caused by an “open” in the wires leading to the regulator or by some cause within the
58
TM 9-1706
HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS 23-24
generator. The generator and wires leading from it would have to be removed and checked to determine the exact cause.
24.	Generator.—a. Description.—The generator is a 12-volt, d-c, 4-brush, 4-pole heavy-duty machine. It is air-cooled by means of the fan which is part of the drive pulley.
(1)	Construction (fig. 31).—The generator field frame has the form of a hollow cylinder. The four pole shoes and four field coils are attached on the inside of this frame. Within the frame-and-
field assembly the armature is supported. One end of its shaft projects through a bearing in a head assembly secured to the extremity of the frame-and-field assembly, and carries a pulley for the drive belt. The other end, at which the commutator is located, is engaged by a bearing in a second head assembly, which holds the commutator brushes and closes the opposite extremity of the frame-and-field assembly. A bracket is screwed to the bottom of the frame-and-field assembly and to the side of the engine, fastening the generator in place with the commutator at the rear and the pulley to the front in line with the engine fan. Both head assemblies have openings and on the rear face of the drive pulley are vanes which force air through the generator from end to end to ventilate and cool it. On top of the frame-and-field assembly, near the commutator end, are insulated, shielded terminal posts to which the armature and field windings are separately attached.
(2)	Functioning.—The generator converts a small amount of mechanical energy which is carried to the battery, where it is stored for future use. In actual operation some of the energy is used directly from the generator, but for explanatory purposes it is assumed to flow from the generator to the battery and then to be drawn from the latter.
(3)	Specifications.
Make------------------------------------- Electric Auto-lite Co.
Model_____________________________________12-volt.
Ordnance No------
Manufacturer’s No. White No__________
Rotation_________
B167664.
GDJ-4802-A.
344910.
Clockwise viewed from
driven end.
Type of winding--------------------- Shunt.
Voltage_____________________________12.
Ground------------------------------- Negative.	,
Number of brushes___________________4.
Number of poles.
. 4.
59
TM 9-1706
24
ORDNANCE MAINTENANCE
ARMATURE TERMINAL—------FIELD TERMINAL	HEAD
jHtU	/ARMATURE	/ /BALL BEARING
/DRIVE PULLEY
OILER,	\	\
\ 7A tfwa / 1111111	\
insW *	~
b —	IT ~ — ^'xsTj'	~~ '	lr\ itk	_ J IS
(0= || fl Jo Ug^-Zllll $>177, I I I I I I l I I ITi'Ka	U
^wRiOitt W^ww®p BALL BEARING / p	0	N /
BRUSH SPRING ' / / /	_____LL y , J	'—FIELD COIL
BRUSH ARM-7 / /q	O/	COUNTING BRACKET
BRUSH -'	'------------- RA FSD 1865
Figure 31.—Generator assembly, sectionalized.
60
TM 9-1706
HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS 24
Controlled output.
Fuse_____________
Control__________
55 amperes.
None.
Voltage regulator.
b. Trouble shooting.
Symptoms and probable cause
(1) Noise at engine idle speed.
(«) Broken bearing.
(Z>) Loose pulley.
(c) Loose pole piece.
(cZ) Commutator damaged.
(e) Bent armature shaft.
(2) Low current or no current.
(«) Open circuit in brush connections.
(Z>) Brush sticking in holder.
(c)	Open circuit due to worn brush.
(d)	Open circuit due to broken brush spring.
(e)	Open circuit due to dirty commutator.
(/) Open circuit in field coil.
() Tighten.
(c) Tighten.
(<7) Repair or replace.
(e) Replace.
(a) Check and repair.
(Z>) Loosen and place on commutator.
(e /'
ww"™^Og^^V/
(6)0	fpfji
TT	;
'	^^-FF
' >._■ i, -', I*	---G6
|-	, .. .^ v _. -HH
'
8iX >'	_ZU My ....,.:MO^^
?	S=^ Q . f Z‘"^N%
t ; J
. y	--*
----- . -----KK
. ’ vwj^hw	Ik. jM a
Z-*
rrJV	o	flE >«4**w«9
i ^Ww
QQ\f?	*’
Q^jjO
PP NN RA FSD 1866B MM	LL
1
/
>»
Figuge 38®.—Generator parts.
69
TM 9-1706
24
ORDNANCE MAINTENANCE
Figure 39.—Removing generator pulley nut.
70
TM 9-1706
HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS 24
Figure 40.—Generator pulley removal.
71
TM 9-1706
24
ORDNANCE MAINTENANCE
post. Dismount post from frame-and-field assembly and remove field coils. Push post out of field coil terminal by hand. Remove terminal insulator and bushing.
(12) Remove armature terminal post. %6-inch open end wrench.
Remove hex nuts, lock washer, shield housing, plain washer, and insulating washers from armature terminal post. Remove post, two large pieces of insulation, and insulating bushing. Remove generator main brush control lead assembly.
Figure 41.—Thin socket wrench for removal of held terminal hexagon nut.
e. Maintenance and adjustments.— (1) General.—The external circuit must be kept in good condition. Defective wiring and loose or corroded connections at the battery, starting motor, ammeter, and elsewhere in the circuit must be checked for and eliminated when found. Loose or corroded connections in the charging circuit will cause high voltage which would result in injury to the generator and regulator, as well as shorten battery, light bulb, and distributor point life. Poor connections in the field circuit will cause a low generator output. Use rosin flux in making all soldered connections. Never use an acid flux on electrical connections.
72
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HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS 24
(2) Lubrication.—Ball bearings at both ends of armature are packed half full with heat-resisting grease, but should be given a few drops of oil, engine, SAE 30, every 1,000 miles.
(3) Commutator.— (aj If the commutator is dirty, it may be cleaned with a strip of No. 00 sandpaper. Never use emery cloth to clean the commutator. All dust must be blown from the generator after the commutator has been cleaned.
(6) If the commutator is rough or out of round or has high mica, remove the generator from the engine and disassemble the armature from the generator. Turn the commutator down in a lathe, removing only sufficient material to true up the commutator and remove roughness and high mica. Undercut the mica as shown in figure 42. The commutator should be inspected at least every 10.000 miles.
Figure 42.—Undercutting armature commutator.
(4) Brushes.— (a) Check the brush spring tension by hooking a scale in the hole at the end of the brush arm and take reading as the arm leaves the brush. Excessive spring tension will cause the commutator and brushes to wear rapidly. Low spring tension will cause a reduced generator output, arcing, and burning of the commutator and brushes.
(&) Check the lead connections at the brushes to see that they are tight. A poor connection in the charging circuit will cause the generator to build up excessive voltage which may result in burned field
73
RA PD 10958
TM 9-1706
24	ORDNANCE MAINTENANCE
or armature windings. A poor connection in the generator field circuit will cause a low output.
() If the generator does not show grounding, check the field circuit for open circuit by connecting test lamp across field terminals. If test lamp fails to light, test each coil separately to determine faulty coil after generator is disassembled.
(
xNV ■ ;.xkJBbk ' ' :Jits..
Figure 45.—Voltage and current regulator, installed.
80
SCREW - BCAXIBD --------1
IMU T* ** 0 B AX i Ft	11 *—*..■muni
WASHER, LOCK - 6ECXIH -»	ra fso i868
TM 9-1706
HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS
25
RELAY CUT-OUT 13.5 VOLTS CURRENT REGULATOR 55 AMPS VOLTAGE REGULATOR 14.5 VOLTS
O .040 TO .042" WHEN
-----------n---------n-- =O------------n_________P POINTS ARE JUST AIR GAP .060 TO .065-X .047 TO .049" WHEN ,______J. I BREAKING
,--------1-------Lk	POINTS ARE JUST >	---ZT_ _
.........	1-----1	BREAKING n < 30 OHMS ,	1	--- Ljj......	;
« <......:..' > ।	<---------; i > H <	. .z; i
<___________ I J <----------------- l—1 S > <_______________ I
(	49.7 OHMS	■>	I	>	(---------'	„ < S	(	,5-8 OHMS ;	I
r-----~-----)	1	<	। OHM ,-------->	'5 > <	---------)	।
(___________'	i	 (______________ ।
r	)	I	>	f----------*	S (	1
<-----------I	*•	) I.----1  (------------
(-----------s I	<	) j 80 OHMS r (----------)	1
I---	I	(---------' I	<------------1 I
■ o BATTERY	I ARMATURE	/----1
1----------------1	.	--—GROUND
A______________r
I L fZe \
RAPD 40076
Figure 46.—Regulator (type VRH) and generator wiring diagram.
476794°—42---6
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ORDNANCE MAINTENANCE
Voltage and current regulator assembly, top view.
lesistance is automatically switched into the field circuits of the generator and the output is thus reduced.
(Z>) The circuit breaker assembly, which is at the left end of the unit (viewed from the side with the three terminals), consists of an armature carrying contact points, which are connected to the battery, and controlled by an electromagnetic core on which are wound a few turns of relatively large wire, making a current coil. One end of this coil is connected to a fixed contact and the other to the armature of the regulator. A spring attached to the armature of the circuit breaker normally keeps the fixed and the movable contacts separated. The circuit breaker also includes a voltage coil on the same core, made
82
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HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS 25
Figure 48. Voltage and current regulator assembly, front view.
up of a few turns of fine wire wound in the same direction as the current coil and connected in shunt to a ground.
(c) The current regulator assembly (center) and voltage regulator assembly (right) each consists of a similar magnetic core with a hinged armature carrying a contact which is held against a fixed contact by a spring. The core of the voltage regulator assembly has a fine wire winding in shunt with the field coils of the generator. The core of the current regulator assembly has a winding of thick wire in series with the armature of the generator and the current coil of the circuit breaker or cut-out relay. Additional resistance for the field windings of the generator are also present, but are so arranged that, as long as the contacts of both current regulator assembly and voltage regulator are closed, this resistance is not effective.
(2) Functioning.— (a) When the engine has been started by the battery and the starting motor, the battery voltage drops and the generator operates to replenish that part of the energy of the battery which has been consumed in starting. As soon as the generator speeds up and its voltage exceeds the battery voltage, armature current flows first through the current regulator assembly and then by way of the shunt or voltage coil of the circuit breaker (or cut-out relay) to ground.
83
RA PD 10954
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ORDNANCE MAINTENANCE
Figure 49.—Voltage and current regulator assembly, rear view
Thus the magnetic core of the circuit breaker is energized, and the armature is attracted to bring the contacts together. Current then flows from the generator, through the current coil of the circuit breaker which is m series with the battery and generator, and restores energy to the battery. The current coil and voltage coil of the circuit breaker are wound in the same direction, and one reinforces the other. As the battery voltage increases, less current flows through the current coil, a though the effect of the voltage coil on the magnetization of the core is continued. When the battery voltage approaches its maximum, it opposes the further flow of generator current through the current coil of the circuit breaker. As soon as the generator stops, or slows down to a point where its voltage is less than the battery voltage, current from the battery flows through the current coil but in the reverse direction. The current and voltage coils now oppose each other and the magnetic effect on the armature is no longer great enough to overcome the spring. The contacts then separate and the battery and generator are disconnected. As long as the battery is being charged le generator will supply the electrical system.
(J) While the battery is being charged by the generator the current regulator assembly and voltage regulator assembly keep the current
84
RA PD 10969
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HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS 25
and voltage of the generator within safe limits. At predetermined points, the current regulator coil or the voltage regulator coil will act to cut in resistance in the generator field circuit and weaken the field. The armature of each assembly will then vibrate rapidly so that the generator voltage and current will never be permitted to exceed their maximum selected values. As the generator voltage is kept virtually constant, less current is forced into the battery as its voltage is increased; thus the charging operation is properly performed. The voltage regulator is compensated for temperature variations by means of a magnetic bypass to give a higher voltage under cold operating conditions than under hot operating conditions. This is necessary, as a higher voltage is required to charge a cold battery than a hot battery.
(3) Specifications.
Make__________________________________ Electric Auto-lite Co.
Model_________________________________Single core, vibrator.
Ordnance No___________________________B167663.
Manufacturer’s No------------------------VRH-4102A.
White No______________________________ 344909.
Ground________________________________Negative.
Maximum current-----------------------55 amperes.
Radio shielded.
b. Quick checks (inspection of unit installed on vehicle).—If regulator is thought to be faulty, remove the cover, make a close visual inspection of the following, and make all possible corrections at once.
(1)	Evidence of burning or abnormal high temperature at the coils, contacts, insulation, external terminals, or any other point. This test should be made with a magnifying glass.
(2)	Loose connections which result from poor soldering.
(3)	Loose nuts on the bottom of the magnet cores, or loose rivets or screws. All nuts and screws must have lock washers.
(4)	Loose contact points.
(5)	Misalinement of contact points.
(6)	Bent armature either at the contact or hinge end. The armature should be perfectly straight from one end to the other.
(7)	Field frame bent.
(8)	Bent armature hinges.
(9)	Stripped or crossed threads on any screw or nut.
(10)	Corrosion due to scale or acids.
(11)	Evidence of water having been inside of cover.
(12)	Incorrect, bent, or distorted armature adjusting spring. In case of doubt it is recommended that the spring be replaced.
(13)	Broken gaskets.
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ORDNANCE MAINTENANCE
(14)	Incorrect wiring connections between units.
(15)	Shunt leads and terminal on circuit breaker armature must be free and not interfere with armature movement or touch tension spring.
(16)	Metal transfer or built up on regulator contact points.
c. Trouble shooting.
Symptom and probable cause	Probable remedy
(1) Overcharged battery or
high charging rate.
(«) Short circuit between output circuit and field.
(5) High voltage setting at regulator.
(2) Low battery charge and low or no charge rate.
(a) Loose connections.
(Z>) Frayed or damaged wires.
(.
---------~**	(C. __Qi I----------------RR
j -r	-7 X* ''Vr- XW	II’’-GG : I	--------00
.-	-^ -	X	|	__-______pp
-•; v II	8 uhh 3 IIIl jbhhf?™
';.. c	1/ »p| 'r' ’1. p -^W
-X €j^ fc 9	^*1-----' oj ^8 J, tffeW!™—I-------------NN
Nw	- ■■■'X. 7 °	y Bl ■,......... J
p ®g<^	5 Ik	. F3__________e aWL.	y -w ~ -^-^WSMBr - /”-«WS
o	Ihgi:	—KK	‘ UJl'jb- 't£— --MM
, ~w ^** «t» •*	' 4S	, *	4 W.^	*	J*
W '#5 .	,«■.<•	t s.	W	|®	W.
R M^Wto- , .	P^Km»»««s8SS® . . ---—	-W| >	vw-™rTTrr-».	ra pD 32g3
’ •	•	: /	U	fl	?r
I	■HLL
(¥,	■•■'.
■
.- ^rvj.............r u.-.^y •
Figure 51.—Voltage regulator, exploded view.
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HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS 25
A.	Armature assembly—AL-VRH—1080A.
B.	Spring—AL—VRA—84.
C.	Jumper—AL—VRH—19.
1). Terminal—AL-X—767.
Screw—BCOX2AE.
Washer, lock—BECXIE.
E.	Washer—AL—VRH—25.
F.	Armature assembly—AL—VRH—1061A.
G.	Spring—AL-VRA—17.
L. Support—AL—VRA—74.
J.	Coil assembly—AL—VRH—2008.
K.	Armature assembly—AL—VRH—1043.
L.	Suport—AL-VRA—74.
M.	Spring—AL-VRA-17.
N.	Screw—BCFX2AE.
Washer—BEBXID.
Washer, lock—BECXID.
P.	Screw—AL-VRA—15.
Nut—AL-VRA—16.
Q.	Coil assembly—AL—VRH-3035A.
R.	Frame—AL—VRA—68.
S.	Bracket—AL-VRH—35.
Screw, Mach—BCFX2AD.
Washer—BEBXID.
Washer, lock—BECXID.
T.	Terminal (bat.)—AL-VRA—5.
U.	Bracket—AL—VRA—73.
V.	Terminal (arm.)—AL-VRA-17.
W.	Resistor—(1. OHM)—AL-TC-51A.
X.	Bracket—AL—VRH—36.
Y. Screw, mach.—BCKXIFD.
Washer, lock, BECXID.
Z. Terminal (fid.)—AL-VRA-63.
AA. Screw, mach.—AL—8X—137.
Washer, lock, BECXIH.
BB.	Bracket—AL—VRA—60.
Button—AL—VRA—59.
CC. Regulator assembly—AL—VRA—2071.
DD. Support assembly—AL-VRA-1057.
EE. Plate—AL-VRA-87.
Screw—AL-8X-453.
FF. Cover—AL-VRA—2.
GG. Gasket—AL-VRA-50.
HH. Nut—BBAXIA.
Washer, lock—BECXIG.
JJ. Screw—BCOX2AE.
Washer—BEBXIE.
Washer, lock—BECXIE.
KK. Gasket—AL-VRA-51.
Insulation—AL-VRA-52.
LL. Case with stud assembly—AL-VRA-1072.
MM. Resistor—(80 OHM)—AL-TC-51M.
NN. Screw—BCNXIFE.
Washer—BEBXID.
Washer, lock—BECXID.
PP. Resistor (30 OHM)—AL-TC-51L.
QQ. Nut—BBBXIA.
Washer, lock—BECXIG.
RR. Resistor (15-OHM)—AL-TC-51J.
(4)	Remove jumper between Soldering iron. voltage regulator and current regulator assemblies.
Heat soldered ends and disconnect jumper.
(5)	Remove voltage regulator Screw driver.
assembly.	%6-inch socket wrench.
UnscrewT two round head machine screws with lock washers on top of insulation to disconnect leads of voltage coil. Then remove nut and lock washer from lowrer end of core and lift out voltage regulator assembly.
(6)	Remove armature spring None.
and adjusting screw assembly from voltage regulator assembly.
Release upper end of spring from armature. Remove adjusting screw nut and lift out spring and adjusting screw assembly.
(7)	Remove voltage regulator Screw driver. armature assembly.
Remove twyo machine screws with lock washers and plain washers and lift off armature assembly.
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(8)	Remove voltage regulator Screw driver. support assembly.
Unscrew three machine screws with lock washers from front of frame and remove support assembly.
(9)	Remove voltage regulator 7/16-inch open end wrench. coil assembly.
Remove hex nut from end of core at bottom of frame and take out coil assembly.
(10)	Remove current regulator Screw driver.
assembly.	%-inch open end wrench.
%6-inch open end wrench.
Remove machine screws, lock washers, and plain washers holding resistor to current regulator and circuit breaker and lift off resistor. Disconnect coil lower lead by removing hex nut, lock washer, and clip. Disconnect coil upper lead by removing machine screw, lock washer, and plain washer. Then remove nut and lock washer from lower end of core and lift out current regulator assembly.
(11)	Remove current regulator None. adjusting screw and spring.
Unhook upper end of spring by hand from armature. Remove adjusting screw nut and lift out adjusting screw and spring.
(12)	Remove current regulator Screw driver. armature assembly.
Extract two machine screws, lock washers, and plain washers, and lift off armature assembly.
(13)	Remove current regulator Screw driver. support, core, and coil.
Extract three machine screws, lock washers, and plain washers holding support to frame. Remove hex nut holding core to frame. Remove support and core by hand from frame and take out end insulating washers, coil, and paper sleeve. Pull out core from support.
(14)	Dismount circuit breaker %6-inch open end wrench. assembly.
Remove hex nut and lock washer from core at bottom of insulation. Lift off circuit breaker assembly.
(15)	Remove circuit breaker None. adjusting screw and spring.
Unhook upper end of spring by hand from armature. Remove adjusting screw nut at lower end of spring and lift out adjusting screw and spring.
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HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS 25
(16)	Remove circuit breaker Screw driver. armature assembly.
Extract two fillister head screws, lock washers, and plain washers holding armature assembly to frame and lift off assembly.
(17)	Disconnect circuit breaker Soldering iron.
coil leads from point bracket.
Melt solder at bracket and pull out leads.
(18)	Remove circuit breaker Screw driver.
point bracket assembly and insulation.
Extract two machine screws, lock washers, plain washers, insulating washers, and insulating bushings and remove bracket assembly and insulation.
(19)	Remove circuit breaker Screw driver. frame, support.
Extract two fillister head machine screws and lock washers and lift off support by hand from top of frame.
(20)	Remove circuit breaker %6-inch open end wrench. coil assembly.
Unscrew hex nut on bottom of frame and pull coil assembly out of frame.
(21)	Separate circuit breaker None.
series coil and shunt coil assembly.
Lift out shunt coil assembly, series coil, and bottom insulation.
f. Maintenance and adjustments.—-*(1) After any faults indicated by visual inspection have been corrected or ascertained and regulator continues to be defective, remove the unit and use the following procedure to locate defects.
(«) Connect test lamp in series with battery. Attach one of the test leads to BAT terminal and the other test lead to the ARM terminal of regulator. Close the circuit-breaker contacts and if lamp lights the circuit is not broken.
(Z>) Attach the test leads to the ARM and FIELD terminals of regulator; the lamp should light if circuit is not broken. Separate the current regulator contacts first and then the voltage regulator contacts; the light should go out in both instances, indicating no shorts in circuit.
(2)	If any of these tests do not give the proper results, detach the complete base assembly, remove the resistors, disconnect each circuit, and make a continuation test and ground test of each individual circuit. If an ohmmeter is available, each circuit should be tested for resistance and if the measured resistance does not come within
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25	ORDNANCE MAINTENANCE
specifications, see (6) below. If the carbon resistors do not have enough resistance they may be filed until the proper resistance is obtained. Replace resistors, or make any necessary repairs.
(«) Remove the armature adjusting springs and adjusting brackets from current regulator and voltage regulator. Be sure springs are taken off before brackets, otherwise the hinges of the armatures will be bent and damaged.
(Z>) Fasten each armature down with clamp, or hold by hand, and insert a piece of paper % inch wide between the contact points. Connect spring scales to contact spring and take scale reading at instant when paper can be moved between the contacts by pushing. The pressure of the contact points of both current and voltage regulator should be 7 to 8 ounces.
() Connect regulator to generator and battery circuit.
RA PD 10971
Figure 52.—-Checking armature air gap with pin gage.
Figure 53.—Checking contact point gap.
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ORDNANCE MAINTENANCE
Figure 55.—Checking gap of circuit breaker points.
94
’ x ' \	W
RA PD 10973
Figure 54.—Checking circuit breaker armature air gap.
TM 9-1706
HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS 25
() Disconnect ground lead of current regulator and connect an ohmmeter between this point and the stationary contact. See (6) below for correct resistance reading.
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(6) Service data.
Carbon resistors______
Resistance :
R1 marked 80.
R2 marked 15 R3 marked 30.
R4 marked 1__
Circuit breaker:
Resistance of voltage winding-.
Armature air gap______________
Contact point gap_____________
Points close__________________
Points open___________________
four used.
_ 76 to 84 ohms.
_ 13.5 to 16.5 ohms.
_ 28 to 32 ohms.
_ 0.9 to 1.1 ohms.
49.7 ohms.
0.060 to 0.065 inch.
0.015 inch minimum.
13.0 to 13.5 volts.
0.5 to 4.0 amperes discharge.
Voltage regulator:
Resistance of winding.
Armature air gap_____
Contact point gap_______
Pressure of contact points Operating voltages:
Allowable variation_
Temperature F_______
15.8 ohms.
0.040 to 0.042 inch (measured when points are just breaking).
0.010 inch minimum.
7 to 8 ounces.
Volts
Current regulator: Armature air gap
Plus or minus 0.15 volt.
60°, 70°, 80°, 90°, 100°, 110°, 120°.
14.51, 14.48, 14.45, 14.39, 14.36, 14.33, 14.30.
Contact point gap________
Pressure of contact points Operating amperes_______
g. Regulator assembly.—Tools: %6-inch open end wrench. Screw driver.
(1) Install circuit-breaker series coil and shunt coil assembly.
Place bottom insulation and series coil in position in frame. Insert shunt coil assembly into series coil so that lower threaded end of
0.047 to 0.049 inch (measured when points are just breaking).
0.010 inch minimum.
7 to 8 ounces.
54 to 56 amperes.
Soldering iron.
%6-inch open end wrench.
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core passes through hole in bottom frame. Secure assembly with hex nut at bottom of frame.
(2)	Install circuit-breaker Screwdriver. frame support.
Place support in upper end of frame, over upper end of core, so that slot and hook are closer to front of frame. Secure support with two fillister head machine screws and lock washers.*
(3)	I ns t all circuit-breaker Screw driver. point bracket assembly.
Lay insulation against front of frame, place bracket over it, and secure with two fillister head screws with lock washers, plain washers, insulating washers, and insulating bushings.
(4)	Connect circuit-breaker coil Soldering iron. leads to point bracket assembly.
Insert coil leads into projection of point bracket assembly and solder securely.
(5)	Install circuit-breaker ar- Screw driver. mature assembly.
Place armature assembly in position so that front end is under frame support hook. Secure assembly to frame by inserting one fillister head machine screw with lock washer and plain washer through each lead assembly terminal and armature support into frame.
(6)	Install circuit-breaker ad- None. justing spring and, screw.
Hook spring on projection at rear of armature and pass screw down through hole in lower end of support. Attach round nut to bottom of screw.
(7)	Mount circuit-breaker as- %6-inch open end wrench. sembly.
Insert threaded lower end of core through riveting base assembly and secure with lock washer and nut.
(8)	Install current regulator Screw driver.
support and coil assembly.	%6-inch open end wrench
Insert flanged core through support from top side. Slip onto core one insulator washer for top of coil, paper sleeve, coil, and
476794°—42---7
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ORDNANCE MAINTENANCE
insulator washer for bottom. Turn coil so that when support is mounted terminals will be at left, when frame is viewed from front.
(9)	Install current regulator Screw driver. armature assembly.
Pass front end of spring through adjusting bracket and secure armature assembly to back of frame with two fillister head screws and lock washers.
(10)	Install current regulator None. adjusting spring and screw.
Hook end of spring on projection at rear end of armature and pass screw through lug at bottom of assembly. Install round adjusting nut on bottom of screw.
(11)	Mount current regulator %6-inch open end wrench. assembly.
Place assembly next to circuit-breaker assembly, passing threaded end of core through riveting base assembly. Secure assembly to base with lock washer and nut. Connect current regulator coil top lead to front of base with machine screw, flat washer, and lock washer. Connect bottom leads of current regulator and circuit breaker together with clip, lock washer, and nut at rear of base.
(12)	Install resistor “7”.	Screwdriver.
Secure one end of resistor to circuit-breaker resistor bracket and the other end to current regulator resistor bracket with one machine screw, lock washer, and plain washer at each end.
(13)	Assemble voltage regula- %6-inch open end wrench. tor coil and mount in frame.
Insert core through cdil, install insulation at bottom, and insert threaded end of core through hole in frame. Secure assembly to frame with nut. Coil leads should be at left.
(14)	Install voltage regulator Screw driver. support assembly.
Place support assembly in position in frame, fitting upper end of core in opening with magnetic shunt piece to rear. Secure assembly to front of frame with three fillister head machine screws and lock washers.
(15)	Install voltage regulator Screw driver. armature assembly.
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Pass front encl of spring through adjusting bracket at front of frame and secure assembly to back of frame with two plain washers, lock washers, and fillister head machine screws.
(16)	Install voltage regulator None. adjusting spring and screw.
Hook end of spring on projection at rear of armature and pass screw through lug at lower end of assembly. Install round adjusting nut on bottom of screw.
(17)	Mount voltage regulator %6-inch open end wrench. assembly on riveting base assembly.
Insert threaded end of core through insulation and secure assembly with nut and lock washer at bottom of insulation.
(18)	Connect voltage regulator Screw driver. coil lead and, -fixed contact lead.
Fasten eyelet terminal of fixed contact lead to internally threaded tubular rivets at front of riveting base assembly with roundhead machine screws and lock washers. Connect voltage regulator coil front lead in a similar manner to rivet at rear of base.
(19)	Connect jumper to voltage Soldering iron. and current regulator assemblies.
Solder ends of jumper to projections on insulated ends of contact springs of voltage and current regulator armature assemblies.
(20)	Install three resistors on Screw driver. bottom of riveting base.
Using two roundhead machine screws, lock washers, and plain washers for each resistor-, mount resistor “80” crosswise with one end on FIELD terminal and opposite end on connector strip. Mount resistor “15” crosswise with one end on opposite end of connector strip and the other end on metal piece receiving lower end of current regulator core. Mount resistor “30” lengthwise of riveting base assembly with one end fastened to same metal piece and the opposite end to terminal which is attached to tubular rivet of voltage regulator lead.
(21)	Install complete regulator Screw driver. base assembly.
Set complete base assembly on case and fasten with four roundhead machine screws and lock washers through corners.
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ORDNANCE MAINTENANCE
(22)	Connect voltage regulator Screw driver. and circuit-breaker leads to
ground.
Pass roundhead machine screw with plain washer and lock washer through eyelet terminal of each lead and hole in riveting base assembly and fasten screws to case.
(23)	Install case cover.	%6-inch open end wrench.
With gasket in position place cover on case with studs projecting through cover and secure with two nuts and lock washers on studs.
h. Regulator installation.—Tools: %-inch open end wrench. %-inch socket wrench.
Screw driver.
(1)	Install regulator assembly and, shield on vehicle.
Channellock pliers. %-inch open end wrench.
%-inch socket wrench.
%-inch open end wrench.
Place regulator assembly in position on dash, place shield on regulator base feet, and secure both to dash with cap screws, lock washers, and nuts.
(2)	Connect generator field and Screwdriver. armature leads and filter lead to Channellock pliers. regulator.	%-inch open end wrench.
Insert leads through shield and connect them to respective regulator terminals with lock washers and fillister head machine screws. Care should be taken when connecting filter lead unless battery has been disconnected. Secure generator and filter conduits to shield with conduit coupling nuts.
(3)	Install shield, cover.	Screw driver.
Secure cover to shield with plain washers, lock washers, and machine screws at corners.
Section VIII
ELECTRICAL—IGNITION SYSTEM
Paragraph
Description of system__________________________________________ 26
Trouble shooting for system____________________________________ 27
Ignition coil and filter_______________________________________ 28
Distributor___________________________________________________  29
Ignition shielding___________________________________________   39
Spark plugs______________________•____________________________ 31
26.	Description of system (fig. 56).—a. The ignition system comprises a coil having a primary winding for periodic connection to
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HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS 26-28
the spark plugs of the engine in proper order; and a secondary winding to be energized from either the battery or generator. The connections between the active source of power and the coil are controlled by an ignition switch on the dash.
b. The primary circuit of the coil from the source of current is completed at each instant of firing in the engine by means of the distributor, which has a movable contact connected to the primary circuit and a stationary contact connected to ground. These contacts come together and are separated by the action of a cam in the distributor. At the same time the rotor in the distributor, which is joined to the secondary winding, completes a circuit to each spark plug in succession, and fires the charge in the particular cylinder where the mixture of air and gas is fully compressed. The high-voltage leads between the coil and the spark plugs consist of wires in shielded conduits attached to the plugs and the coil and to metal inserts in the cap on top of the distributor. The upper half and the lower half of the distributor are enveloped in radio shielding.
27.	Trouble shooting for system.
Symptoms and probable cause	Probable remedy
a.	Engine missing slightly or sluggish.
Conduit defective, loose, or Check and repair or replace, short-circuited.
b.	Engine backfires.
Crossed plug conduits.	Install in correct firing order.
28.	Ignition coil and filter.—a. Description.—The coil is mounted in a shield assembly at the left side on the front of the dash. The coil radio filter is also mounted in the shield at the rear of the coil.
(1) Construction.— (a) The ignition coil consists of an encased primary and secondary winding in the form of a fixed unit, having three terminals at one end. The filter lead is connected to the positive terminal, the distributor high-tension lead sets into the center terminal, and the distributor breaker point lead is connected to the negative terminal. The conduits for the distributor leads are attached to the shield cover by conduit coupling nuts.
Note.—The internal construction of the coil is such that no attempt should he made to rebuild a faulty or damaged coil.
101
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28
ORDNANCE MAINTENANCE
.__
MIRaW r
/	11 v> W m rSC®-.
/ / \	/ I -Lr\ t —^a
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id—D C	-Z'-'
'''^"'	' RA PD 75i 2
A.	Battery assembly—WB—4376.
B.	Cable assembly—WI-348739.
C.	Conduit, w/wire assembly—TI-A-26378.
D.	Distributor assembly—AL-IGW-4147.
E.	Conduit assembly—TI-S204-1808.
F.	Conduit assembly—TI-S204-1700.
G.	Conduit assembly—TI-S204-3104.
H.	Conduit assembly—TI—S204—2900.
J. Conduit assembly—TI—S204-2512.
K.	Conduit assembly—TI-S204—2104.
L.	Switch assembly—DM—2980.
M.	Ammeter assembly—SW-SG96647.
N.	Gage, fuel, assembly—SW-95622.
P.	Fuse (50-amp.)—BZ-3730-4.
Q.	Coil assembly—AL-CF-4001.
R.	Conduit assembly—TI-S204-3800.
S.	Cable assembly—WI-3685.35.
Figure 56.—Ignition system.
(&) The filter consists of a coil connected in series with the ignition coil and a condenser which is connected in the circuit at one end and grounded at the other end.
(2) Functioning.— («) The ignition coil steps up or multiplies the voltage of the primary coil, at the instant when this circuit is broken at the distributor, to the high value needed for the electric discharge at the gaps of the spark plug. The secondary voltage is as many times as great as the primary voltage as the ratio between the large number of turns of the secondary and the small number of turns of the primary winding. The high secondary voltage is produced by electromagnetic induction, and is impressed on each spark plug in turn as the primary coil circuit is broken at the distributor.
(&) The filter, in circuit with the primary coil and the shield, and the shielding of the conduits reduce and shield the radio apparatus in the car against interference.
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HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS 28
(3) Specifications.
Ignition coil:
Make________________________
Model_______________________
Type------------------------
Ordnance No-----------------
Manufacturer’s No-----------
White No____________________
Primary voltage-------------
Shield and filter assembly:
Make________________________
b. Trouble shooting.
Symptoms and probable cause
(1) Arcing between high- and low-voltage terminals causing engine to miss.
Excessive moisture on end of coil.
(2) Coil will not give spark at plugs, failing to start engine.
(«) Open circuit in primary or secondary circuit or either circuit grounded.
(&) Windings grounded inside casing.
(c) Short-circuited turns in primary or secondary coil or high-voltage break-down in secondary.
() Replace coil.
() The direction of rotation of the distributor is clockwise when viewed from the top. As the engine speeds up. the governor advances the cam to make the ignition take place earlier in the stroke. The purposes for which the manual adjustment of the distributor is provided are to control ignition when adjusting the carburetor, to facilitate starting in cold weather or by hand, and to eliminate knocking when carbon has accumulated in the engine or a low-grade fuel is used.
(3)	Specifications.
Make_________________________
Model________________________
Ordnance No__________________
Manufacturer’s No____________
White No_____________________
Number of cylinders.
Rotation___________
b. Trouble shooting.
Auto-lite.
Semiautomatic.
B167666.
AL-16W-4147.
347361.
6.
- Right-hand (viewed from top)
Symptoms and probable cause
(1) Engine will not start.
(a) Breaker points not closing.
(3) Breaker points defective.
(c) Breaker arm grounded.
(<7) Defective rotor or cap.
Probable remedy
(a) Check and adjust (see e (7) below).
(&) Check and replace, if necessary.
() Breaker contact points pitted.
(Z?/.
Remove nut holding distributor arm to bracket on water pump and lift out- assembly. Note exact position of rotor so that distributor can be installed in correct timing position.
d. Disassembly of distributor (fig. 61® and @).—Tools:
Screw driver.
%-inch open end wrench.
%-inch open end wrench.
%-inch drift.
Hammer.
Thin-nosed pliers.
%6-inch open end wrench. Punch.
Arbor press.
%-inch diameter.
Arbor.
110
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HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS 29
(1) Remove condenser assembly None.
from base.
Disconnect lead of condenser by hand from terminal post. Take off condenser shield with condenser assembly inside.
(2) Remove lower-half distrib- Screw driver.
utor shields from base.
Figure 60.—Removing distributor cap and shielding assembly.
Take out four screws with lock washers. Dismount two shields. (3) Detach rotor assembly from None.
cam.
Pull rotor assembly off upper end of cam-and-stop-plate assembly.
(4) Remove terminal post and %-inch open end wrench. breaker arm assembly from base.
Remove remaining binding nut, small lock washer, plain brass washer, shakeproof washer, and insulating washer from terminal post and lift out breaker arm assembly. Pull out terminal post, carrying with it the insulating bushing (sleeve), insulating bushing (washer), square plain metal washer, and post insulation (strip). Remove the two bushings, washer, and strip from terminal post.
Ill
RA PO 10985
TM 9-1706
29
ORDNANCE MAINTENANCE
RA FSD 1863A
A.	Cap assembly—AL-1GB-1240.
B.	Rotor assembly—AL—1GB—1239.
C.	Spring and hinge assembly—AL-1GB—1007.
*D. Arm assembly—AL—1GW—3028.
E. Screw—BCNXIFB Washer, lock—BECXID.
*F. Plate assembly—AL-1GB—2010.
G. Cam and stop plate assembly—AL-1GW-2100R.
H. Spring—AL-1 GB-37.
J.	Spring—AL—1GB—297.
K.	Weight assembly—AL—1GW—1063R.
L.	Washer—AmiGW-92.
M.	Washer—AL—1GS—104.
N.	Shaft assembly—AL—1GW—2047 RF.
P.	Base assembly—AL-1GW—2123.
Q.	Cup, grease.
R.	Washer—AL-1G-816A.
S.	Screw—BCGX2BD.
T.	Arm assembly—AL—1GB—2296.
U.	Washer, lock—BECXIG.
V.	Nut—BBAX1A.
W.	Screw—BCFX2DR.
X.	Washer—AL-1G-688A.
Y. Washer—AL-1 G-687.
Z. Washer—AL-1G-688.
AA. Nut—AL—8X—163.
BB. Screw—AL-1G-750.
CC. Insulation—AL—1GB—21.
DD. Post—AL-1GW-39.
EE. Washer—AL-1GW-54.
FF. Bushing—AL-1GW-38.
GG. Bushing—AL—CB-140.
HH. Washer—AD-1GB-22.
JJ. Washer—AL-X-1270.
KK. Washer—BEBX1BE.
LL. Washer, lock—BECXIE.
MM. Nut—BBMXIC.
’Points (service set)—AL—1GW-3028S.
Figure 61®.—Distributor assembly, exploded view.
112
FSD 1S63A
TM 9-1706
HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS 29
L	w M N
, no ■ .. w I
O5>'
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ww,
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X
\	.... _v ________________t
V. .....
/ — ",i" "" 1 .o
_—-	(0)'—~~~Y
RA FSD 1863®	1'^#	V.^
Figure 61®.—Distributor assembly, exploded view. 476794°—42-8	Ug
TM 9-1706
29	ORDNANCE MAINTENANCE
(5)	Remove breaker plate as- Screw driver. sembly and spring and hinge assemblies.
Extract three screws and lock washers holding breaker plate assembly. Remove two spring and hinge assemblies and lift out complete breaker plate assembly.
(6)	Remove breaker screw point %-inch open end wrench. from plate assembly.
Unscrew nut and breaker screw point and dismount point from breaker plate.
(7)	Remove drive gear from %-inch drift.
shaft assembly.	Hammer.
Drive out pin holding gear to shaft and remove gear and thrust washer.
(8)	Remove drive shaft gov er-	None.
nor and cam assembly from base.
Lift drive shaft, governor, and cam assembly out of base assembly and slide thrust washer off shaft.
(9)	Disassemble drive shaft Thin-nosed pliers. governor and cam.
Free governor springs from anchor lugs and remove cam lock spring ring. Lift off cam-and-stop-plate assembly from shaft assembly and remove governor weights.
(10)	Remove grease cup from %6-inch open end wrench. base.
Unscrew grease cup and base assembly.
(11)	Remove advance control Punch.
arm assembly.	Hammer.
Screw driver.
%6-inch open end wrench.
Punch mark position of arm to base. Loosen clamp nut and slip advance control arm assembly off bearing end of base assembly. Pull off thrust washer.
(12)	Remove bronze bushings Arbor press. from base.	%-inch diameter.
Arbor.
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HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS 29
Press bronze bushings from base assembly.
e. M aintenance.— (1) Inspection.—After every 2,000 miles examine the distributor carefully as follows:
(«) Check contact points for condition and clearance. If they are gummy or dirty, clean them well. Check cam follower and if found to be worn, replace breaker arm assembly.
(6) Inspect cap. Wipe away dust or oil within cap and base. If cap is not burnt at any point, or if metal inserts are burnt only at the tips and not excessively, cap can be put to further use. If cap shows cracks or carbon streaks, which are evidence of arcing, it should be replaced.
() Turn point screw in or out until 0.020 gage just fills gap when cam separates points fully (fig. 63).
(Zy.
Mount breaker arm assembly on pivot journal, using one drop of light oil on journal. Hook end of spring on terminal post between head and metal washer. With scale on end of breaker point, set spring tension (see e(7) above). Tighten binding nut on outer end of terminal post to clamp spring securely.
(10)	Adjust breaker points. %-inch open end wrench.
Set breaker screw point, and lock with binding nut, to have a contact gap of 0.020 inch (±0.002) ; cam angle setting 38°.
(11)	Install rotor assembly. None.
Fit key inside rotor to key way and press rotor down upon cam.
(12)	Install lower radio shields. Screw driver.
Fasten two lower-half shields to outside of base assembly with two screws and lock washers each. Place shield, having condenser directly over terminal post. Slip terminal of condenser onto terminal post.
(13)	Install drive gear.	Drift.
Hammer.
Slip thrust washer onto shaft, place gear in position on shaft, and secure with pin. Peen over end of pin. End play of shaft can be changed by using different size thrust washers.
g. Installation of assembly.—Tools:
%6-inch open end wrench. %-inch open end wrench.
Screw driver.	Channellock pliers.
(1)	Mount distributor on water %6-inch open end wrench. pump casing.
Place shaft into water pump casing so that when gear on distributor meshes with gear on water pump the rotor is in the same position as when distributor was removed. If engine has been moved while distributor was out, it will be necessary to retime distributor as explained in e(5) above. Place spring washer between two plain washers in position on control arm and fasten distributor to bracket on water pump with special screw.
(2)	Connect dash control wire. Screwdriver.
Push wire through hole in machine screw in end of control arm and secure with screw.
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HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS 29-30
(3)	Connect primary wire.	%-inch open end wrench.
Screw driver.
Channellock pliers.
Remove condenser shield and place low-voltage wire over condenser lead terminal on terminal post. Secure with hex nut and lock washer. Fasten conduit coupling nut to shield. Replace condenser shield and secure with two screws and lock washers.
(4)	Install cap and upper Screw driver. shield.
With high-voltage wires in proper position, place cap over distributor and secure with clips. Twist upper distributor shield clockwise to clamp it, and then tighten locking screw.
30.	Ignition shielding.—a. Description (fig. 64).—Shielding is provided for the distributor and all wires connected to it, and for the spark plugs.
(1)	Construction.—(a) The shields for the distributor are the two lower-half shields and condenser shield attached by screws to the distributor base assembly; and the upper-half shield covering the cap of the distributor and secured by a screw and stud in slots on the lower-half shields (fig. 60).
(5)	The shields for the wires are in the form of metal conduits. Each conduit encloses one of the wires and has a ferrule and an internally threaded coupling nut on each end. By means of the coupling nuts the conduits are attached to the distributor, upper-half shield and distributor base, and to the shields for the spark plugs, and to the shield of the ignition coil.
(58037
I'Kn iti: 66.—Radio shielding, installed.
125
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31
OR DN ANCE M A I N TE N AN CE
31.	Spark plugs.—a. Description (fig. 67).—The spark plugs are of a commercial type with gap that can be set by bending the side electrode.
(1)	Construction.—Each plug consists of a metal shell within which is fixed an insulator with a central electrode stem. The shell is threaded at one end to screw into the cylinder head; at its inner end it carries a fixed, bent, side electrode that is separated from the
CABLE ASSEMBLY
RUBBER GASKET ASSEMBLY
SPARKPLUG GASKET
RA PD -3720
Figure 67.—Spark plug with shielding, installed.
CONE SHIELD HIGH TENSION LEAD SUPPORT INSULATOR COUPLING NUT CONTACT SPRING ASSEMBLY SPARKPLUG SHIELD SPARKPLUG
inner end of the central stem by the spark gap. The stem is sealed in the insulator and has a terminal on its outer end for connection with the high-voltage shielded conduit leading to the distributor cap. A copper gasket is placed at the threaded end when the plug is screwed into position.
(2)	Functioning.—When the circuit is closed from the spark coil to the plug, a spark jumps at the gap and ignites the gas in the combustion chamber.
126
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HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS 31
(3)	Specifications.
Make_______________________
Model______________________
Ordnance No________________
White No___________________
b. Trouble, shooting.
Symptoms find probable cause
(1)	Engine missing slightly, sluggish or irregular performance.
(«) Improperly adjusted spark gap in plug.
(b) Loose, leaky plug threads.
(2)	Failure to give spark.
(«) Insulation broken at one end.
(ft) Side electrode worn excessively.
(c) Plug carbonized at inner end.
(- 'X	- if 2 W	%
'	\	SOCKET WRENCH
’ wSmPLIM INSULATOR — TI-A-27487
\ j ‘	| SHIELD - LOWER -
\	1	TI-A-20315
PLUG AND SHIELD REMOVED
>	J
H ,	*	■»
RA PD..80351
Figure 68.—Spark plug removal.
d. Maintenance and, adjustments.— (1) After every 500 miles of operation, the spark plugs should be removed and the following checks made:
(«) Check for cracked or blistered insulation and replace plugs if any is evident.
128
TM 9-1706
HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS 31
(&) Check for dirty or worn electrodes. Clean dirty electrodes with a brush or by scraping, and replace plugs with worn electrodes.
(c) Check the spark gaps and if they are too large or too small, set gaps to 0.025 inch, using a gage and pliers (fig. 69).
Figure 69.—Measuring spark plug adjustment with gage.
(2)	A running engine has a certain rhythm. If a spark plug of a regularly firing cylinder is shorted out, a different rhythm is produced. Remove shield cap and short out each plug. Note the result on the operation of the engine. If a cylinder is already missing no change will be noted when its plug is shorted out. If a spark plug is thought to be faulty, it should be removed and tested in a spark plug tester.
(3)	After 10,000 miles of operation, new spark plugs should be installed.
(4)	For effects of different operating conditions on spark plugs, see figures 70Q and @ and 71.
(5)	The following cautions should be observed:
(«) Do not bend center electrode.
(Z>) Never touch plugs or high-voltage cables while engine is running.
476794°—42---9
129
|
TM 9-1706
31
ORDNANCE MAINTENANCE
I - BROKEN INSULATOR TOP
’CARELESS HANDLING :
2 - SPLIT INSULATOR
Mending center
ELECTRODE
iMhkvV	>• \
U %*'	Ml kJI-"w JF...
■ . . ..■.■>•■■■
3 - SIDE ELECTRODE WORN	<
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RA PD 3572E
Figure 70®.—Effects of operating conditions on spark plugs.
130
TM 9-1706
HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS 31 5 - STREAKED INSULATOR TOP f BLOW-BY)
7 - CARBON COATING (RICH MIXTURE, OIL PUMPING. OR COLD PLUG) ---------
8 ■ SOOT COATING
(PROLONGED OPERATION AT NO LOAD)
ra pd 3..szaa
Figure 70®.—Effects of operating conditions on spark plugs.
131
6 - RUSTY-BROWN COATING ( HIGH SPEED OR
...—... HEAVY LOAD)
TM 9-1706
31
ORDNANCE MAINTENANCE
......................................... ~ ”"................—----- •—~-ro COLD (OILY CARBON)------SLIGHTLY HOT (REDDISH DEPOSITS)
SLGHTLY COLDCDRY BLACK SOOT)-St f |£--------------------TOO HOT (BLISTERED OR GLASSY!
ssa^
Jr 4 w
CORRECT INSDI ATOR COLOR	TOO HOT (AFTER PROLONGED OPER'
^UHHLCi NbUL^ASUH CULUK_--—yi^	|gj	AT ION .AT HIGH SPEED OR UNDER
(LIGHT. TAN)	J J*	W IK HEAVY LOAD)
. RA PD 3572$
Figure 71.—Effects of operating conditions on spark plugs.
132
TM 9-1706
HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS 31-32
(c) Do not use graphite or other lubricants on threads of spark plugs.
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).
(2)	Field coil test for ground.—See paragraph 24e(7) (a).
(3)	Individual field, coil test for grournd.—See paragraph 24e (7) («•).
(4)	Armature test for ground (fig. 79).—See paragraph 24 e(7) (a).
(5)	Armature test for short circuit.—If the. trouble has not yet been located, check the armature for short circuit, using a “growler.” A thin strip of steel, such as discarded hacksaw blade, held in place over the armature core as the armature is turned in the growler, will vibrate if a short circuit exists in the armature (fig. 81). Replace if necessary.
(6)	Insulated brush holder test for ground.—Place one test prod on cover and other on insulated brush holder. If lamp lights, brush holder is grounded and should be replaced.
h.	Service data.
Brush spring tension______________42 to 53 ounces.
Torque tests:
No load speed with Bendix_____ 4,800 rpm with 11 volts
Locked torque:	and 65 amperes.
350 amperes_________________4 volts—11.1 pound-feet.
540 amperes-----------------6 volts—17.3 pound-feet.
750 amperes-----------------8 volts—23.5 pound-feet.
37. Reassembly of components.—a. Starting motor.—Tools:
Pliers.
Soldering iron.
Screw driver socket.
Arbor press.
9/16-inch open and wrench. %-inch open and wrench. Screw driver.
(1)	Mount springs in commuta- None.
tor end head assembly.
Slip inner ends of springs into split ends of brush holders and lift free end of each spring until it rests on brush holder.
146
TM 9—1706
HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS 37
RA PD 10975
Figure 79.—Testing starting motor field.
147
RA PD 10976	WM /
Figure 80.—Testing armature for ground. •
TM 9-1706
37
ORDNANCE MAINTENANCE
RA PD 10970
Figure 81.—Armature
test for short circuit.
(2)	Attach terminal post and field coil terminal to upper left field coil.
Pliers.
Soldering iron.
Clamp one end of terminal on
Force post through coil terminal.
end of conductor at corner of coil and solder.
(3)	Mount pole shoes and field coils in field-and-frame assembly.
Screw driver socket.
Screw driver.
Put hole shoe in each coil, place coils in positions marked, and attach with one screw in each shoe. Slip large insulating washer on post over field coi] terminal, add insulating bushing, and thrust post through hole from inside of frame assembly. Put insulation strip under upper and lower right coils along edge of openings in field-and-frame assembly. Tighten four screws.
(4)	Unite coils in series at drive Pliers.
end of field-and-frame assembly. Soldering iron.
Use separate connecter for upper and lower right coils. Join and solder all ends of lower and upper right, and lower and upper left coils.
(5)	Attach two blushes to field, Pliers.
coils.	Soldering iron.
Join end of upper right coil at inspection opening on field-and-frame assembly to middle of additional connector, and a complete brush and lead to each end of this connector. Pinch and solder at all points.
148
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HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS 37
(6)	Insert armature into field- None. and-frame assembly.
Pass armature into frame-and-field assembly.
(7)	Insert commutator end head Arbor press. bushing.
Press bushing into commutator end head.
(8)	Replace commutator end None. head assembly.
Slip thrust washer on armature shaft at commutator. Put bearing in head assembly over armature shaft. Bring notch in head assembly to receive dowel pin on frame-and-field assembly.
(9)	Mount brushes in brush None.
holders and set springs on brushes in commutator end head assembly.
Insert brushes attached to field coils through inspection openings of field-and-frame assembly into insulated holders on assembly and two additional brushes into remaining holders; then set free ends of springs upon them.
(10)	Replace intermediate bear- Arbor press. ing and bushing.
Press bushing into bearing, and put bearing thrust spacer, thrust washer, and intermediate bearing assembly with bushing on armature shaft at drive end.
(11)	Secure terminal post.	%6-inch open end wrench.
Apply insulating washer, plain washer, lock washer, hex nut, lock washer, and second hex nut to post outside of frame-and-field assembly. Tighten nuts.
b. Bendix drive.
(1)	Place drive head on arma- None.
ture shaft.
Insert Woodruff key in slot and slip on drive head over key, lining screw hole up with hole in shaft.
(2)	Place drive spring and %-inch open end wrench. gear-and-shaft assembly on armature shaft.
Slip on spring and gear-and-shaft assembly. Secure spring to drive head and drive head to shaft with dowel and hex head screw
149
TM 9-1706
37-39	ORDNANCE MAINTENANCE
and lock washer. Secure spring at opposite end to gear-and-shaft assembly with hex head screw and lock washer. Bend lock washer ears against screw heads.
(3)	Replace bushing in pinion Arbor press. housing.
Force bushing into end bearing of housing.
(4)	Attach pinion housing. Screw driver.
Slip housing over Bendix drive and insert intermediate bearing into housing. Line up dowel pin on housing with bearing. Slip long end of armature shaft through bushing. Line up hole in housing with dowel pin on field-and-frame assembly. Pass two long screws through commutator end head assembly and field-and-frame assembly into housing and tighten.
38.	Installation of assembly.—Tools:
%-inch open end wrench.
%6-inch open end wrench.
a.	Mount starting motor on en- %-inch open end wrench. gine.
Attach motor to flywheel housing with three studs, three nuts, and three lock washers.
b.	Connect motor to battery ca- %6-inch open end wrench. ble.
Remove one nut and lock washer from terminal post. Attach terminal of cable to post and secure with lock washer and nut.
Section X
ENGINE (STRIPPED)
Paragraph
Description-----------------------------------------------------------  39
Trouble shooting------------------------------------------------------- 40
Removal of assembly____________________________________________________ 41
Removal of accessories_________________________________________________ 42
Disassembly of engine (stripped)_______________________________________ 43
Maintenance and repairs________________________________________________ 44
Assembly________________■__________________:___________________________ 45
Installation of accessories_____________’______________________________ 46
Tests and adjustments__________________________________________________ 47
Engine installation____________________________________________________ 48
39.	Description (figs 82 and 93).—The engine is a model JXD Hercules gasoline unit and is a four-cycle, six-cylinder, L-head type.
150
TM 9-1706
HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS 39
151
aS 2
fl 0) fl
fl ft
8
I ®
1.S bD

AND INTAKE-	rWIO	\ PE. ASSEMBLY - WL348746
HM-45804E	I-
PUMP, FUEL AND I z uZ	f
VACUUM, ASSEMBLY-I	'“Jit//w O W/L. | f
AC-J 537105
''	-w— B"
I-*** .................... ’	• "W' IL ?
I	T\	■■% \ wt; I MW
F \ : y	/ \ d	ill ■
X-Y	’	’’	fe ’	.
, I !•	■-	- /	8	HM-4Q390CSY
Y*\	I- 9 ■ I ■/CAMSHAFT - HM-45686A
fw	wrv;J[- R' ffefig /
E ll|p T'''v lT±nwMilitT'fffeB y :g|::.^4| KoRM sWafe ,..1	111	K/ Wh 311964 ......	.
r w
J	PULLEY - WU325753
' JAW - HM-40806A b _ oino
'*-‘-*** w«<>'	RA P» 8108 ..
Figure 87.—Gasoline engine, dismounted, front view.
(7)	The camshaft is of the cast alloy type and is enclosed in the upper half of the crankcase. It is mounted in four steel-backed babbitt-lined bearings of the continuous ring type. The crankshaft-to-camshaft drive is through helical cut gears. The camshaft gear is keyed to the camshaft and held in place with a nut and special lock washer. The crankshaft gear is keyed to the crankshaft extension and is held in place with a tight press fit.
156
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HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS 39
CYLINDER AND CRANKCASE ASSEMBLY ~ HM-42310DS
MANIFOLD, EXHAUST AND	'
INTAKE - HM-43804E
< Ik JBI
.	HEAD, CYLINDER
■ ;ag *	ft	HM-459210
H /
I ®	...	’	- . . L - s 1|
J3B& > GEAR, PUMP, WATER-
.	'■<	HM.22.95B
..
* ::*W:
gear, camshaft-
HM-22049B	e...............	«
“mHF*
Zy C	J
.	A»S J®
z
4 : y*" -
/ ■■ ■■ ■
,	HM-40135B
GEAR, CRANKSHAFT- ™	4*	\
HM-22039B	J	'	PAN, OIL, ASSEMBLY-
HM-40375D
HM-42176D
RA PO 8H0
Figure 88.—Gasoline engine, seetionalized, front elevation.
157
TM 9-1706
39
ORDNANCE MAINTENANCE
(8)	The flywheel is bolted and doweled to the flange on the crankshaft and forms a part of the clutch housing (fig. 89). The starter ring gear is shrunk onto the flywheel.
(9)	The intake and exhaust manifold are cast in one piece (fig. 84). The intake manifold has a hot spot incorporated to provide for a shorter warming-up period.
jr	i .a., ■
\. wi V	~
((• > j It
* wifex WLz ?w/	> - j
'-WwFft ^2^ ■ *^Q**^X' % g.
~ \	ft a’’**7/
■<	g
E E-x
•J w y>
M u» re 2
»	E
>
■c	'
O
5
_S
Figure 89.—Gasoline engine, dismounted, rear view.
(10)	The oil pump is of the two-gear positive type, having steel gears pressed on steel shafts. The oil pump is bolted directly to the center main bearing web, the suction tube extending into the strained oil compartment (fig. 90). The oil is raised from the strained oil reservoir and pumped into a channel drilled in the case. From this point it is distributed to the main bearings through drilled passages and thence to the connecting rod bearings through the drilled crankshaft.
158
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HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS 39
► TO OIL PRESSURE GAGE
• t
i—CONNECTING ROD
!;
[-OIL PASSAGES IN BLOCK
11	\	*■ >	fiSSgl
H | S M -- II '• -9 -/•' = d /' n~| frjjh "J^1 | |	'bX'j	.'Bnlgfe— CAMSHAFT
JI ‘TlMmB vULii/Jr dl IMU>xHkN:
c ft—z-WJ
CRANKSHAFT-W. .	^7	m
MlM \ w	\ r
■■	—	---- Xx	-7^=^	\ CONNECTING
---------- -------- . ,„, DrAD|Kir	ROD BEARING \x ———  ---------- ■	MAIN BEARING |_
h -	---01L PUMP
—	---7-----	SCREEN
01L PAN T=--- ' --	---LUBRICATING OIL
X..... ,-------- S	RA PD 7529
Hct-4	,._.ZZ_-DRAIN PLUG
Figure 90.—Gasoline engine lubricating system.
159
TM 9-1706
39-40
ORDNANCE MAINTENANCE
b. Specifications.
Make----------------------------
Model_____________________
Type--------------------------
Number of cylinders-----------
Bore__________________________
Stroke________________________
Piston displacement__________
Compression ratio____________
Rated horsepower (N. A. C. C.)_
Firing order-----------------
Maximum blip at maximum rpm_
Crankcase____________________
Capacity
40. Trouble shooting.
Symptoms and probable cause
a.	Lack of power.
(1)	Low or poor compression.
(2)	Poor ignition.
(3)	Poor carburetion.
(4)	Air cleaner restricted.
(5)	Overheating.
(6)	Improper grade and viscosity of oil.
b.	Poor compression.
(1)	Valves worn.
(2)	Valve seats worn or pitted.
(3)	Piston rings weak, broken, stuck, or worn.
(4)	Tappets sticking.
(5)	Tappets set too close.
(6)	Leaky spark plugs.
(7)	Cylinder head loose.
(8)	Cylinder head gasket leaking.
(9)	Worn pistons.
(10)	Worn cylinders.
(11)	Valve stems worn.
(12)	Valve guides worn.
Hercules gasoline.
JXD.
L-head.
6.
4-inch.
4%-inch.
320 cubic inches.
6.5 to 1.
38.4.
l-5-3-6-2-4.
110 horsepower at 3,000 rpm. With block.
6 quarts.
Probable remedy
(1)	See below.
(2)	See section VIII.
(3)	See section XI.
(4)	Clean mesh element in gasoline.
(5)	See section VI.
(6)	Change to correct grade.
(1)	Grind valves.
(2)	Cut new seats.
(3)	Replace rings and correct cause of sticking.
(4)	Clean guides.
(5)	Set clearance at 0.006 inch.
(6)	Tighten plugs in head.
(7)	Tighten head.
(8)	Replace gasket.
(9)	Replace worn parts.
(10)	Rebore cylinders.
(11)	Replace valves.
(12)	Replace guides.
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HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS 40
(13)	Valve springs weak or broken.
(14)	Valve timing incorrect.
c.	Excessive cylinder and piston wear.
(1)	Improper grade and viscosity of oil.
(2)	Lack of oil.
(3)	Dirty oil.
(4)	Overheating.
(5)	Piston improperly installed and fitted.
(6)	Piston rings not properly fitted to piston groove and cylinder wall.
(7)	Piston rings stuck in piston grooves or broken.
(8)	Air cleaner not clean, allowing dirt to enter combustion chamber.
(9)	Carburetor fuel mixture too rich.
d.	Bearing failures.
(1)	Crankshaft bearing j ournal rough or out of round.
(2)	Crankshaft oil passage restricted.
(3)	Bearings sprung.
(4)	Bearings loose or improperly fitted.
(5)	Crankshaft out of aline-ment.
(6)	Bearings out of alinement.
(7)	Lack of oil.
(8)	Low oil presure.
(13) Replace springs.
(14) Correct timing.
(1)	Change oil to correct grade and viscosity.
(2)	Keep oil at correct level.
(3)	Always change dirty oil.
(4)	See section VI.
(5)	Correct or replace piston.
(6)	Install new rings and fit correctly.
(7)	Clean or replace rings.
(8)	Clean air cleaner mesh and sump.
(9)	Replace worn jets.
(1)	Grind or replace shaft.
(2)	Clean passages and line.
(3)	Replace sprung inserts.
(4)	Adjust mains 0.0025 to 0.0035 inch and rods 0.0015 to 0.002 inch.
(5)	Straighten, or replace if necessary.
(6)	Aline bearings with shims, or replace if necessary.
(7)	Add oil or check oil pump.
(8)	Adjust pump to deliver 5-pound pressure at idling and at least 25-pound pressure at running speed. Fit bearings properly.
476794°—42----11
161
TM 9-1706
40
ORDNANCE MAINTENANCE
(9)	Overspeeding engine.
(10)	Restricted oil passages.
(11)	Bent connecting rod.
(12)	Improper oil.
e. Burned valves and seats.
(1)	Tappets set too close.
(2)	Weak valve springs.
(3)	Improper valve timing.
(4)	Excessive carbon deposits around seat and valve head.
(5)	Valves sticking in guides.
(6)	Improper type valves.
(7)	Valve head too thin, causing hot sections.
(8)	Valve seats too narrow.
(9)	Lean mixture.
(10)	Overheating.
(11)	Low-grade fuel.
/. Valves sticking.
(1)	Improper valve clearance.
(2)	Insufficient clearance between valve stem and guide.
(3)	Valve springs weak.
(4)	Valve springs broken.
(5)	Valve stems scored or dirty.
(6)	Gummy deposits from inferior fuels or oils.
g. Overheating.
(1)	Ineffective cooling.
(2)	Lack of oil.
(3)	Carburetor choke valve partly closed.
(9)	Continuous operation at maximum speed or close to it is to be avoided. Exercise caution when going down grade.
(10)	Clean oil passages and line.
(11)	Replace rod.
(12)	Use correct oil. (SeeTM 9-1705.)
(1)	Set at 0.006 inch.
(2)	Replace springs.
(3)	Time properly (see valve timing).
(4)	Clean carbon.
(5)	Clean stems and guides. Replace parts as required.
(6)	Use genuine parts.
(7)	Replace valve.
(8)	Cut seats to correct width.
(9)	Clean carburetor. Check float adjustment.
(10)	See section VI.
(11)	Use good quality fuel.
(1)	Set at 0.006 inch.
(2)	Ream guides for proper clearance.
(3)	Replace springs.
(4)	Replace springs.
(5)	Replace or clean valves.
(6)	Clean. Use better grade fuel or oil.
(1)	See section VI.
(2)	Add oil.
(3)	Adjust controls.
162
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HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS 40
(4)	Correct timing.
(5)	Check muffler and tail pipe.
(1)	Install new rings.
(2)	Tighten or replace.
(3)	Tighten.
(4)	Use recommended grade oil. (See TM 9-1705.)
(5)	Rebore cylinders.
(6)	Overhaul cylinders.
(7)	Adjust or replace bearings.
(8)	Install new rings.
(9)	This condition will correct itself.
(10)	Replace rings.
(11)	See section VI.
(12)	Clean rings of carbon. Replace if necessary.
(13)	Adjust pump pressure.
(1)	Use correct oil.	(See
TM 9-1705.)
(2)	Adjust correctly. (Oil pressure 5 pounds at idling and at least 25 pounds at running speed.)
(3)	Clean screen.
(4)	Adjust crankshaft bearings to 0.0025 to 0.0035 inch and rod bearings to 0.0015 to 0.002 inch.
(5)	Overhaul oil pump.
(6)	Replace shaft.
(1)	Clean carbon from engine.
(2)	Clean carbon from engine.
(4) Improper valve timing.
(5) Exhaust line restricted.
h.	Excessive oil consumption.
(1)	Piston rings worn or broken.
(2)	Crankcase gasket loose.
(3)	Front gear case loose.
(4)	Poor grade of oil.
(5)	Cylinder walls worn.
(6)	Cylinder bore out-of-round or excessive taper.
(7)	Main or rod bearings worn or loose.
(8)	Ring gaps too great.
(9)	Ring gaps ]ined-up.
(10)	Rings poorly seated.
(11)	Overheating.
(12)	Oil ring slots clogged with carbon.
(13)	Excessive oil pressure.
i.	Low oil pressure.
(1)	Improper oil.
(2)	Pressure regulating plunger worn or clogged.
(3)	Oil pump screen clogged.
(4)	Excessive crankshaft and connecting-rod bearing clearance.
(5)	Oil pump worn.
(6)	Idler gear shaft worn .
j.	Popping, spitting, and spark knock.
(1)	Excessive carbon deposits.
(2)	Hot spot in cylinder head (carbon formation or clogged water passage).
163
TM 9-1706
40—41
ORDNANCE MAINTENANCE
(3)	Improper valve timing.
(4)	Ignition timing incorrect.
(5)	Carburetion incorrect.
(6)	Spark plug gaps too wide.
(7)	Tappets set too close.
(8)	Exhaust valve head too thin, causing hot sections.
(9)	Weak valve springs.
(10)	Valves not seating properly.
(11)	Piston and rings in poor condition.
(3)	Check valve timing.
(4)	Correct timing (see Sec. VIII).
(5)	Check carburetor (see Sec. XI).
(6)	Set plugs at 0.025 to 0.028 inch.
(7)	Set at 0.006 inch.
(8)	Replace valve.
(9)	Replace springs.
(10)	Grind valves, and cut seats if necessary.
(11)	Overhaul.
41. Removal of assembly.—Tools:
Pail.
Pliers.
%6-inch open end wrench.
Heavy-duty square shank screw driver.
Length of rope.
Hoist.
%6-inch box wrench.
%-inch open end wrench.
Screw driver.
%-inch socket wrench.
%-inch socket wrench with universal attachment.
%6-inch open end wrench.
%-inch open end wrench.
%-inch open end wrench.
%-inch open end wrench.
Channellock pliers.
%6-inch socket wrench.
Thin screw driver.
%-inch thin wall socket wrench.
%-inch open end wrench.
%6-inch socket with speed handle.
Length of %-inch manila rope (at least 14 feet).
1%6-inch socket wrench.
1%6-inch open end wrench. Wood blocks.
Hammer.
a. Drain radiator.
Pail.
Pliers.
Open drain cock or lower left-hand hose connection and drain water into pail or on ground.
164
TM 9-1706
HERCULES JXD GASOLINE ENGINE EOR SCOUT CARS 41
b.	Remove hood.	9/i6-inch °Pen end wrench.
Heavy-duty square shank screw driver.
Length of rope.
Hoist.
Remove three elastic stop nuts and bolts at rear of center panel of hood. Remove nut and bolt on inside of shutter frame, near the top, on each side of frame. Use rope and hoist to lift off hood with top of shutter frame left on hood. Hood can also be slipped over front of car by three men.
c.	Remove shutter assembly. %6’incb box wrench.
Heavy-duty screw driver. %-inch open end wrench. Chain hoist.
Remove bolts and nuts holding shutter frame to engine side armor plates. Disconnect shutter control on lower right side of radiator. Lift shutter frame straight up and out.
d.	Remove radiator hose con- Screw driver. nections.
Loosen clamps holding inlet and outlet radiator hoses and pull hoses loose from radiator.
e.	Remove radiator.	%-inch socket wrench.
%-inch socket wrench with universal attachment.
Chain hoist.
Disconnect radiator from cross member by removing holding stud nuts, springs, washers, and pads. Then disconnect stay rods at frame by removing nuts from stay rod bolts underneath car on the bottom side of the top frame flange. Remove radiator assembly from car by lifting up and slightly forward (fig. 91).
f.	Remove heater inlet and re- Screw driver. turn hoses.
Loosen clamp holding inlet hose to cylinder head connection and pull off hose. Then loosen clamp holding return hose to water pump connection and clip holding hose at cylinder head. Pull hose from water pump connection.
g.	Disconnect battery.	%6-inch open end wrench.
Remove cap screws and lock washers holding battery compartment cover and lift off cover (fig. 92). Loosen nuts clamping cable
165
TM 9-1706
41
ORDNANCE MAINTENANCE
Figure 92.—Battery compartment cover removal.
166
Figure 91.—Radiator removal.

TM 9-1706
HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS 41 terminals to battery terminals and pull off cables from terminals. Always pull off negative cable first (fig. 93). Tape cable terminals. h. Remove carburetor air horn, %-inch open end wrench.
and rubber hose assembly.	Screw driver.
Loosen clamp holding hose to air cleaner outlet. Then loosen cap screw holding air horn to carburetor air inlet. Lift horn from carburetor and remove horn and hose assembly (fig. 176).
i.	Remove pipe assembly fuel %-inch open end wrench. pump to carburetor.
Shut off fuel tank supply at transfer shut-off valve. Disconnect flanged tube nuts at fuel filter inlet connection and at fuel pump outlet connection and remove pipe assembly.
j.	Disconnect carburetor con- %6-inch open end wrench. trots.	Screw driver.
Remove nut and lock washer holding throttle control rod to throttle lever and lower rod. Then loosen screws holding choke and throttle controls at carburetor and pull out controls (fig. 94).
k.	Remove pipe a s s e mb I y %-inch open end wrench. {check valve to inake manifold).
Disconnect flared tube nuts at check valve intake fitting and at intake manifold fitting and remove pipe assembly (fig. 95).
I.	Disconnect fuel feed line and %-inch open end wrench. windshield wiper pipe assembly %-inch open end wrench. at fuel pump.
Disconnect main fuel line fitting at fuel pump inlet fitting. Then disconnect inverted flared tube nut holding windshield wiper pipe assembly to vacuum side of fuel pump (fig. 190).
m.	Remove right-hand funnel Screw driver.
assembly.	9/i 6’inch open end wrench.
Loosen clamp holding funnel assembly to ventilator box. Remove cap screw and lock washer holding funnel support bracket to frame and lower funnel assembly.
n. Disconnect exhaust pipe at %-inch open end wrench. manifold.
Remove two brass nuts holding exhaust pipe flange to manifold flange.
167
TM 9-1706
41
ORDNANCE MAINTENANCE
Figure 94.—Disconnecting choke wire assembly.
168
MRz
Figure 93. Disconnecting battery terminal.
RrapdjosSj
TM 9-1706
HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS 41
Figure 95.—Vacuum line removal at check valve.
o.	Disconnect cable from start- %6-inch open end wrench. ing motor.
Remove terminal nut and pull cable from terminal.
p.	Disconnect high-voltage and Screw driver. low-voltage wires from ignition %-inch open end wrench. coil.
Remove two coil shielding cover screws and remove cover. Pull out high-voltage wire from coil. Remove nut holding low-voltage wire to coil terminal and pull off wire (fig. 58).
q.	Disconnect manual spark Screw driver. control.
Loosen screw holding control wire to spark control arm and loosen clamp screw at bracket. Pull out spark control.
r.	Disconnect armature conduit Channellock pliers.
with wire assembly at generator. %6-inch socket wrench.
Thin screw driver.
Remove armature condenser from housing and screw off armature conduit nut from housing (figs. 34 and 35). Then remove armature
169
TM 9-1706
41	ORDNANCE MAINTENANCE
terminal post nut (fig. 36), lift off cable terminal from armature terminal post, and pull out conduit with wire assembly.
s.	Remove generator field con- Screw driver.
duit with wire assembly at gen- %-inch open end wrench. erator.	%-inch thin wall socket wrench.
%-inch open end wrench.
Remove generator field terminal housing plug and screw off conduit nut from housing (figs. 32 and 33). Then remove field terminal post nut and pull out conduit, with wire assembly. Loosen clamp holding generator field and armature conduits to engine bracket and free conduits (fig. 66).
t.	Disconnect oil filter pressure y16-inch open end wrench. gage line assemblies.	%-inch open end wrench.
Disconnect oil filter inlet line assembly and oil pressure gage line assembly by unscrewing inverted flared tube nuts from fittings at rear left side of engine block. Break oil filter return line assembly at flared tube fitting located between rear of block and filter.
u.	Remove temperature gage %-inch open end wrench. bulb assembly.
Loosen temperature gage bulb adapter nut at rear left side of engine cylinder head and pull out bulb from adapter (fig. 96).
v.	Remove vacuum line assem- %-inch open end wrench. bly from check valve to booster %-inch open end wrench. hose.	Screw driver.
Unscrew inverted flared tube nut at check valve (fig. 95). Remove cap screw and lock washer holding line clip to rear of engine block. Loosen booster hose clamp screw and pull out line assembly.
w.	Remove left-hand air funnel Screw driver assembly.	%6-inch open end wrench.
Loosen clamp holding funnel assembly to ventilator box. Remove nut, cap screw, and lock washer holding funnel support clamp to bracket and lower assembly.
x.	Disconnect brake vacuum % 6-inch socket with speed handle. booster and bracket assembly.
Remove three cap screws and lock washers holding booster bracket to engine crankcase and lower bracket and booster assembly.
170
TM 9-1706
HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS 41
Figure 96.—Removing temperature gage bulb assembly.
y. Prepare engine for removal. Hoist.
Length of %-inch manila rope (at least 14 feet).
%6-inch socket wrench.
% 6-inch open end wrench.
Tie rope around engine in figure eight. Place hoist in balanced place of rope and remove slack in rope by raising hoist hook. Remove cap screws and lock washers holding transmission to engine bell housing (fig. 97).
z. Disconnect engine supports. Pliers.
%-inch socket wrench.
%-inch open end wrench.
!%6-inch socket wrench. i%6-inch open end wrench.
Remove cotter pins from castellated nuts at rear support bolts and remove nuts, bolts, washers, and right support spring. Remove nuts, lock washers, and cap screws from front engine supports (fig- 98).
171
* E'C |
M RA PO 10899
TM 9-1706
41-42
ORDNANCE MAINTENANCE
aa. Remove engine.	Wood blocks.
Heavy-duty screw driver.
Hammer.
Lift engine until it is free of supports. Block up transmission rigidly in this position. Separate bell housing from transmission and move engine straight forward until clutch assembly is free of splined shaft. Guide engine out of car and place in stand or on blocks (figs. 99 and 100).
Figure 97.—Disconnecting engine bell housing from transmission.
42. Removal of accessories.—Tools:
Screw driver.
%6-inch open end wrench.
Channellock pliers. %-inch socket wrench.
%-inch open end wrench.
%-inch open end wrench. %-inch open end wrench.
%6-inch socket wrench.
172
RrA PD uSool
TM 9-1706
HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS 42
Figure 98.—Disconnecting front engine support.
Figure 99.—Engine removal.
173
S RA PD W90I
Bra pd 74ii
TM 9-1706
42
ORDNANCE MAINTENANCE
Figure 100.—Gasoline engine mounted in stand.
174
RA RD 10828
TM 9-1706
HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS 42
a.	Remove distributor assembly. Screw driver.
%6-inch open end wrench.
Loosen distributor cap shielding locking screw. Pull off distributor cap holding clips, twist cap counterclockwise, and remove it (fig. 101). Loosen clamp holding distributor conduits to engine support bracket and remove conduits from clamp. Remove distributor attaching bracket bolt and lock washer and lift out distributor assembly.
b.	Remove spark plugs and Channellock pliers. shielding.	%-inch socket wrench.
Spark plug wrench.
Unscrew shielding nuts at all spark plug shieldings. Remove cap screws holding shielding conduit support bracket to cylinder head and remove brackets, and distributor cap and shielding assembly. Remove spark plugs (fig. 102).
c.	Remove generator assembly, %-inch socket wrench.
Figure 101.—Distributor cap and shielding removal.
Remove three cap screws and lock washers holding generator frame mounting bracket to engine block, tilt generator to remove fan belts, and then lift out generator and bracket assembly (fig. 103).
d. Remove water pump assem- %-inch socket wrench.
bly and discharge pipe.	%6-inch open end wrench.
175
RA PD 10829
TM 9-1706
42
ORDNANCE MAINTENANCE
Remove four cap screws and lock washers from water pump discharge inlet pipe. Then remove three cap screws and lock washers holding pump assembly to rear of gear housing. Lift out pump assembly, hose assemblyy discharge pipe, and gaskets (fig. 27).
e. Remove fan and bracket as- %-inch socket wrench with exten-sembly.	sion.
Figure 102.—Spark plug removal.
Remove two cap screws and lock washers holding fan bracket to top gear case and lift off fan and bracket assembly (fig. 104).
f. Remove carburetor assembly, %-inch open end wrench.
Remove two carburetor-to-manifold stud nuts and lock washers and lift off carburetor and fuel filter assembly, gaskets, and insulator. Unscrew nuts evenly, lifting carburetor at the same time so that the carburetor will not cock and break base.
176
SOCKET WRENCH "
^INSULATOR - TI-A-27487
SHIELD - LOWER -
-	TI-A-20315
PLUG AND SHIELD REMOVED
PLUG, SPARK WITH GASKET -WI-363H4 Wl-309667
TM 9-1706
HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS 42-43
GENERATOR, ASSEMBLY - Al-GDG-4202 C	BRACKET
* ■
f	tJ' A I ' / SCREW —
4 jMWW ''	'	/ BCBX1CA
•k	i A	'/WASHER, LOCK-
3 'Sifl w ' v	tk /
*\ . . ■■■•■•<■ '	>< v. RENCH
■	‘ Ec&' Ss'S/ . /
« '■ »-w •':»
■'i	; ' , '	■ ,'	’'-’?
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zjs	#a*,*
:Jw	•
* ’ ' ..<■
’	J	",	• •	?' ■"k'SvZ lu. /▼
..W	W ,.	' Hk/
'. 'Lfc ‘g-	jiralilF ’	"l ®I'. ; A
s i s ^e W. < w " Mi v । W
A	*'• . # jp '■■/ e . ^C^Mk.	' RA P0 Si 30
Figure 103.—Generator removal.
■/.'■. :■■■'
/ ^rfsgsg^^^^^WVL. c & s - , , '
1-wr ..	•<* <& Jf Mt ** 3 4
.	®|| fc‘ J' U. ■? ^Bk
..~^.
B । WRENCH
|Lj WRENCH
j; '• f if* r '?iV’
WH| «	.y/Wz^ W
IfaAW ?
wlUPWtl
*■	Lr-V %'v
u
A! L <
FAN, ASSEMBLY- -	‘ . ' jT Wj' K ■	>
sz-a. 105005 |gg| ~^^«MRg	k « Jf
SCREW, CAP - BCAXIEE BRACKET - SZ-B-105008 .
i	- WASHER. LOCK-BECX1M	RA PD 8041
Figure 104.—Fan and bracket assembly removal.
Speed handle.
%-inch open end wrench. Spark plug wrench.
%-inch open end wrench. %-inch open end wrench. Fiber hammer.
34-inch socket ivrench.
Valve spring lifter.
Pliers.
Valve rack.
Screw driver.
a. Drain oil from crankcase.
Vise.
Piston ring expanding tool.
Metal bar.
Pinch bar.
Pulley puller.
2-inch open end wrench.
Press.
Wood blocks.
6-inch extension.
Brass drift.
Pail.
%6-inch open end wrench.
Remove magnetic drain plug from bottom of crankcase and allow oil to drain into pail.
178
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HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS 43
STUD — WI-A14047X
NUT - BBBXIC	MOTOR, STARTING, ASSEMBLY -
WASHER, LOCK - BECXIK	AL-MAU-4006
/	/	i >
i - z /	/
1	/ v
/ /
S, ■:	• • •.	. •	•. ...	-	•
. i. w
I
___ ;
Z$W. ,y:A..X : ■■
\
ADAPTER, STARTING MOTOR - HM-22066A	RA P» 8134
Figure 105.	—Starting motor removal.
b.	Remove oil pan.	%6-inch socket wrench.
Speed handle.
%-inch open end wrench.
Remove cap screws and lock washers holding pan to block and flywheel bell housing, and lower pan and gasket (fig. 107).
c.	Remove oil pump.	%6-inch open end wrench.
Set Nos. 3 and 4 crank throws at top dead center position and remove three cap screws and lock washers holding oil pump to main bearing web. Turn pump one-quarter turn counterclockwise and lift out pump assembly and gasket (fig. 108). See section XII for complete disassembly and servicing of pump.
d.	Remove exhaust and intake %-inch open end wrench. manifold.
Remove 10 brass nuts and plain washers from manifold studs and lift off exhaust and intake manifold assembly and gasket (figs. 109 and 110).
179
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43
ORDNANCE MAINTENANCE
X ■
CAP SCREWS Os) 1
m	. L .
. SOCKET WRENCH WITH SPEED HANDLE
1	\
®w \ y , - '	£
* V ' lv'- It «X*w\
BW 1 ML I	X	. l|k X
:,./b Mik	mJIIwv a
' ■	■■'fl!	*1 ML- ■ *	x' ■■■■ 'slk
WktilwT ■ J
FLYWHEEl -—^Wc * xStC?/ v jiff "
'	xx x^ho
CLCTCH
°?;	RA PD 10830
Figure 106.	—Clutch assembly removal.
e. Remove oil filter and breather %-inch open end wrench. extension pipe.	Fiber hammer.
Remove cap screw and plain w’asher holding pipe to engine head clip (fig. 111). Then tap pipe with hammer as shown in fig. 112 and lift out filler and breather extension pipe and cap assembly.
/. Remove cylinder head. %-inch socket wrench.
Speed handle.
Loosen all cylinder head cap screws with a socket wrench and then use speed handle on wrench to remove cap screws (fig. 113). The oil filler and breather pipe clip will come off tvith its respective cap screw. Lift off cylinder head and gasket.
g. Remove valve covers.	%-inch socket wrench.
Speed handle.
Remove two cap screws from each valve chamber cover (fig. 114). Lift off the covers and cork gaskets which are shellacked to them.
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HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS 43
SCREW, CAP - 8CAXIEB
..	*	WASHER, LOCK - 8ECXIM
//
PLUG, DRAIN - HM-11090-A
iei?c.ioiv HM-40375D (SCA)
| FAN'ASS£MBtY~HM-42176D (SCB)
I	/
/
.■	I	,• &	/
■ •	w. /
v.. - ■	'■'	* L^y i*	■
1	■ •• "; ’■ j| / 1
t	.
/ ■	.	. 3F.
4
V	I . 4Wr
/	J *	H
SCREW, CAP- ^-*/	■ ' -7 's	w
HM447Z0B F If
SCREW, CAP-1	"•	'	'• /Bl
BCAXICB I -s	,.	\
WASHER, LOCK-	.
8EC?'
......-y ...
■ ’
RA PD 8047
Figure 107.—Oil pan removal.
181
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43
ORDNANCE MAINTENANCE
PUMP, OIL, ASSEMBLY—HM-45290CS	fellili	jrA
\	* _.* jM|
\	I
WB -. oi
i it"ti ~~~•—— i
SCREW, CAP WASHER, LOCK	8046
Figure 108.—Oil pump, installed.
182
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HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS 43
STUD - HM-14895A
NUT—HM-848A
at	I WASHER - HM-1388A
| w/|i	r
-- IfrX’ mmJBi
I	1
rr' ■
tA /......-	.......—-
/	’ i \
।	-l
WRENCH MANIFOLD, EXHAUST AND INTAKE-HM-45804E	RA PD 8097
FIGURE 109.—Exhaust and intake manifold removal.
183
MANIFOLD, EXHAUST AND INTAKE - HM-45804E
TM 9-1706
43
ORDNANCE MAINTENANCE
184
I GASKET - HM-4S805B	RA pD 8103
Figure 110.—Exhaust and intake manifold details.
TM 9-1706
HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS 43
185
CLIP - HM-45842A
SCREW, CAP - HM-1048A
WASHER - HM-8191A
RA PD 8098
Figure 111.—Oil filler and breather pipe mounting details.
TM 9-1706
43
ORDNANCE MAINTENANCE
CAP, ASSEMBLY - HM-40038AS —*
PIPE, OIL FILLER BREATHER, EXTENSION- 1	..
‘MOUNTING PAD -	[
GENERATOR BRaCk F;	j
FIBRE HAMMER
L PD	V I I	‘ e.
Figure 112.—Oil filler and breather pipe removal.
186
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HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS 43
J|j	SCREW, CAP-
S’	HM-4H8A	.
I /	> M
/ SOCKET WRENCH
’Jj., fljR
I MEAD, CYLINDER-
HM-45921D
?:u ■. w -	.	. u: M
RAPD81OO
Figure 113.—Cylinder head removal.
187
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43
ORDNANCE MAINTENANCE
St, CAP -	COVER, VALVE CHAMBER - HM-40006B
AXIEK	GASKET- HM-41005B
\ STUDS, MANIFOLD -
f ■	I	HM • 14895A
'V I- /
■ * »z Z	*
v
■■ X
Figure 114.—Valve cover removal.
h.	Remove exhaust and intake Valve spring lifter. valves.	Pliers.
Valve rack.
Place valve spring lifting tool in position with jaw of tool in position under valve spring seat and top of tool centered on valve head as shown in figure 115. Press down on handle of tool until valve spring is fully compressed so that valve pin will be “in the clear” for removal. Remove valve retaining pin and lift out valve. Place valve in a rack suitably marked so that it can be put back in its proper place at assembly. Proceed with all valves in the same manner.
Note.—It is advisable to rotate the crankshaft to a position where each valve to be removed is in the fully closed position. This will permit minimum compression of spring for retainer pin removal.
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HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS 43
i.	Remove valve springs and Screw driver. spring seats.
Set end of screw driver under spring seat and force up seat and spring (fig. 116). Then “flick” screw driver outward so that spring and spring seat clear the tappet. Remove all springs and seats in the same manner.
j.	Remove valve stem guides. Pilot bar.
Hammer.
Insert pilot bar into valve holes through top of block and drive out valve stem guides (fig. 117).
k.	Remove connecting rod and Pliers.
piston assemblies.	%-inch socket wrench.
Hammer.
Rotate crankshaft so that crank throw of piston to be worked on is in its lowest position. Remove cotter pins and castle nuts from connecting rod bearing cap bolts (fig. 118). Lift off bearing cap, shell, and shims. Extreme care should be exercised in removing connecting rod assembly so that cylinder wall will not be scratched or gaged by connecting rod. Place wooden handle of hammer against lower end of connecting rod and push until piston comes out of top of hole (fig. 119). Then pull out on piston and guide connecting rod through cylinder bore with other hand until piston and connecting rod assembly is free of cylinder block. As soon as connecting rod and piston assembly is removed from the block, reassemble connecting rod bearing-cap, shell, and shims to connecting rod (fig. 120). The numbers stamped on connecting rod and cap should be matched. Proceed with remaining assemblies in the same manner.
189
VALVE - EXHAUST - HM-45810A VALVE - INTAKE - HM-40107A
TM 9-1706
43
ORDNANCE MAINTENANCE
190
PLIERS	CLOTH	rA PD 8052
Figure 115.—Valve removal.
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HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS 43
SPRING, VALVE - HM-40008A
SEAT, VALVE SPRING - HM-22013A
SCREWDRIVER
D, VALVE TAPPET - HM-45812A
Figure 116.—Valve spring removal.
RA PD 8053
191
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43
ORDNANCE MAINTENANCE
Figure 117.—Valve stem guide removal.
192
PILOT BAR -
RA PD 8054
TM 9-1706
HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS 43
Figure 118.—Connecting rod bearing cap removal.
476794°—42-----13
193
SOCKET
! Wrench
CAP, CONNECTING ROD BEARING-*
HM- 403918
RA PD 8064
~ ?z f
BOLT- HM-22059A j NUT-HM-21056A
TM 9-1706
43
ORDNANCE MAINTENANCE
194
HAMMER	NOTE POSITION OF HANDS PISTON - HM-40120C
RA PD 8065
Figure 119.—Connecting rod and piston removal.
TM 9-1706
HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS 43
CAP - HM.-40391B
SHELLS, BEARING- /
HM-457078	/	BOLT—HM-22059A
K *	NUT~ HM-21056A
IxeUryX PIN, COTTER - 8FAXICE
\ N* ’^51OT'
i	ROD, ASSEMBLY— 4Q390C5Y
'	ROD - HM-40390C
SHIMS - HM-40556A	\
Y*'	SCREW, HM-22B1A
||g	WASHER, LOCK—ISEAX3C
'X'.
wt: J'
PISTON -HM-4O12OC -*■	'#
PIN - HM-22238A	I’'
RING, Oil REGULATING - HM-39I3A RING, COMPRESSION -HM-3813A
RING, COMPRESSION - HM-42297A -
RA PD 8091 ~ v. - J z -•*'
Figure 120.—Connecting rod and piston assembly, dismounted.
195
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43	ORDNANCE MAINTENANCE
I. Remove piston rings.	Vise.
Piston ring expanding tool.
Clamp piston and connecting rod assembly in a soft-jawed vice. Do not squeeze rod too tight. Then remove the four piston rings as shown in figure 121.
tn. Remove piston pin.	%6-inch socket wrench.
Metal bar.
Hammer.
Remove piston pin clamp screw and lock washer from connecting rod and drive out piston pin as shown in figure 122.
n. Remove starting crank jaw. Pinch bar.
Hammer.
RING groove
KMC tXCANOM ■	F “NGS ' HM-38I3A
.ST tt.	S RING - HM-39I3A
G'v	' z	^^Zzz-zXO.
j||g» gl	-	m	■<,
V If Jx.,’ JR	UP** :
^zw ®MIF >	lO-'W	, .~.
Jh|iR	fl Jw > m-
11	"\yLsl-* 7	if.-*
1 4 •	• ’****^’^**?«“»»*-«.^ ■
RA PD 8092
Figure 121.-—Piston ring removal.
Place hammer handle between one of the crank throws of crankshaft and bottom of cylinder block to prevent crankshaft from turning. Then place pinch bar in hole in crank jaw and unscrew starting crank jaw (fig. 123). Lift out special lock washer.
196
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HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS 43
o.	Remove fan drive pulley. Pulley puller.
%6-inch open end wrench.
Pliers.
With puller center screw backed out as far as possible, bolt puller to pulley with cap screws provided. Anchor crankshaft as explained in n above and remove pulley by turning puller center screw (fig. 124). Remove Woodruff key from crankshaft.
p.	Remove timing gear cover. %6-inch socket wrench.
Speed handle.
Fiber hammer.
Pull off trunnion. Remove cap screws and lock washers holding-cover to engine block (fig. 125). Tap off gear cover and remove gasket (figs. 126 and 127). Pull off oil seal from crankshaft.
q.	Remove idler gear assembly. None.
Pull out idler gear and shaft assembly by hand and remove cork washer (fig. 128).
■■■ ' • •
* A "
1	f 9
B '	> rod, assembly —
| I	HM-40390CSY 'WrwWd'’'
; I
jhip*	!
jflr	BAR
PISTON - HM-40120C
RA Pt> 8093	PIN,'PISTON ~ HM-22238B
Figure 122.—Piston pin removal.
197
TM 9-1706
43	ORDNANCE MAINTENANCE
BAR
hammer:
RA Pt> 8066
JAW, STARTING CRANK-HM-40806A
Figure 123.—Starting crank jaw removal.
198
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HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS 43
’*****k.' -'r
■ ■ x ' '7 1
■» uWSI
- -■ (IfflL ■ .-k—•■*■—
X' J® x\ .
**"'	~	CRANKSHAFT -
HM-45853D
PULLEY PULlfiR
HA
Figure 124.—Fan drive pulley removal.
199
TM 9-1706
43
ORDNANCE MAINTENANCE
■■Illi ■	\	r5SI X «* * Wl
\	vida
‘ <2 X ‘ * ;3? ?llk	WRENCH	. •	&.<’*%? ! ^fer
t '	\	x	।	~
t	'	3j?a s-iF- X
COVER — TIMING GEAR	I A I -	. , T
HM-40333D (SCA)	
I *'■ •• V” ’ \ * 2
-'	jR?	&■> ** fe«l9^>	Z'y i
Z 4 it- - _.............................. fy,U__________1
ffll * vRiolhfefr*. ,.cW‘	I'”"'1I * w
j'O	P	zy
’ Wjk	V ./* X X
Figure 127.—Timing gears installed.
GEAR, IDLER ~ HM-401358
k
0 ’ i
SHAFT -HM-4O136BS
F
SBlIfll^llllIlBIBiiBIOii^lBBI
RA PD 8081
Figure 128.—Idler gear group details.
r.	Remove camshaft.	None.
Note position of punch marks on camshaft and crankshaft gears before removing camshaft. These marks must be in the position shown when engine is assembled in order to give correct valve timing. With engine resting on top face of cylinder block, the valve push rods will be down and will not interfere with removal of camshaft. Pull camshaft assembly straight out as shown in figure 129, being
202
TM 9-1706
HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS 43
careful to guide camshaft so that its bearings will not be gaged or scratched.
s.	Remove valve push rods %-inch open end wrench. (tappets') and dissemble.
Pull out valve push rods by hand as shown in figure 130. Remove push rod screw and nut.
t.	Remove camshaft timing 2-inch open end wrench. gear.	Press.
Wood blocks.
Pliers.
Remove camshaft gear lock nut. Set camshaft and gear in press and press off gear. Remove washer and Woodruff key (fig. 131).
u.	Remove flywheel assembly. Diagonal pliers.
%-inch socket wrench.
6-inch extension.
Long handle.
Fiber hammer.
Wood block.
Anchor crankshaft with wooden handle of hammer. Pull out cotter pins from flange bolt nuts and remove nuts (fig. 132). Remove hammer. Loosen flywheel by bumping it near its outer edge with wood block through starter opening in front of face of bell housing while rotating crankshaft. Lift off flywheel, carrying with it the clutch pilot bearings, dowels, and expansion plugs. In some cases the two large flywheel dowels will remain in flange of crankshaft.
S	J -A’	’’V"’ - W.V45W3O
'Wf W3RMI Wf F	Hr If iw	■ camshah- MIU
' ~ feu
I	RAH) »O7t
Figure 129.—Camshaft removal.
203
TM 9-1706
43
ORDNANCE MAINTENANCE
ROD, VALVE PUSH, ASSEMBLY—HM-45812ASY	f R WF
S/l a I i
i a ।	। t> j v
*	*	*	e / I e „....IF
' 1*	■ ^2T	IT''\«w7
J. wf^”	XxJ LXkw7"^
■•? "ir	: 4 ■ H	¥tx l^jUL	£ ~JBM)' '.u&	j.. 41111	>
.. t. l	: t : r: F • । i"- । ’-
ij.i /.^U' 4 *, SIT' F<*i".	M*' -1 wiI—fa. r !&>■■■
I >'	--J-'- K :	1	®	'?•”	UniMBlti'-
*•’ W"5*W' WSZl’TW-getf
wHHf wbb^ wbbbrw
*	w w ♦	* * e
. .................
RA PD 8072
Fig	removal.
NOTE POSITION OF HANDS
204
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HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS 43
GEAR- HM-22049B
CAMSHAFT - HM-45686A	WASHER - HM-2045A
!
fir e t fee ' '	G K e
[	/ w/
RA PD 8096	OIL PUMP DRIVE GEAR (INTEGRAL)	KEY - BCAX3CC NUT - HM-11023A
Figure 131.—Camshaft group details.
205
TM 9-1706
43
ORDNANCE MAINTENANCE
.	BOLT, HM-22104A
y	BEARING, PILOT-FED-8025 NUT, HM-1656A
J.	i PIN, COTTER - BFAXICE
7 PLUG, EXPANSION -8EDX,AG	/“
B HM-23705C	\ k
A /- ■ '
to.
SOCKET AND '*■“
EXTENSION	.	’ A V	t-
Z	||)
LOCATING ‘	\X\	/
DOWEL HOLE	RA PD 8078
Figure 132.—Flywheel removal.
v.	Disassemble flywheel.	Brass drift.
Hammer.
Wood block.
Drive out flywheel dowels from back side of flywheel, carrying expansion plugs with them. Then drive out bearing using wood block (fig- 133).
w.	Remove engine bell housing, %-inch open end wrench.
Remove four cap screws and lock washers on outside of housing and two on inside of housing (fig. 134). Lift off flywheel bell housing and gasket.
x.	Remove bell housing oil seal. Brass drift.
Hammer.
Drive oil seal out of bell housing.
y. Remove crankshaft and main %-inch socket wrench. bearing shells.	%-inch socket wrench.
Speed handle.
206
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HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS 43
Loosen cap screws on crankshaft main bearing caps and remove cap screws and lock washers, using speed handle (fig. 135). The rear and center main bearing cap screws require a %-inch wrench and the other cap screws require a %-inch wrench. Remove crankshaft main bearing caps, lower shells, and shims. Mark back of each shell with number corresponding to that on its cap so that at assembly correct shell will be used with its corresponding cap if no new shell is required. Lift out crankshaft and timing gear assembly (fig. 136). Remove upper main bearing shells by pushing down with the hands on one end of each shell until it rotates in bearing web enough to get fingers under shell and then lift out shell (fig. 137). Mark shells in the same manner as lower shells.
2	r,	-n
£	8	s
P___.GtsS?	•	i?	S
2	IO’	3 ?	7
I	li/	%i	.!
® s x	J g
§ A	—X
x o -	*.	,
c •	•	. X \
f	. 7
JU
’ t	2
\ ‘ .■	.	9
? XL ■
S	|| 1
1 O	n • Q
M	»
Figure 133.—Flywheel group details.
a. Remove valve push rod {tap- Hammer.
pet) guides.	Pilot bar.
Drive out push rod guides from inside of block as shown in figure 138.
207
TM 9-1706
43
ORDNANCE MAINTENANCE
aa. Remove crankshaft timing Gear puller.
gear.	Pliers.
Set puller screws in tapped holes in gear and pull off gear. Remove Woodruff key.
> x* d	GASKET —
BELL HOUSING -	HM-22065B
HM-24427D	A
fl I
7	' . '	’	'	'■
■ r- <' - ~
Q	1h
,<4-x ClU/7 J
■	1	x	■-■■WxjE
■	4 '	'	wrJ
X
5	L.. j
SCREW, CAP - BCAXIEC WASHER, LOCK - Bf-CXIM	RA Po 8068
Figure 134,—Flywheel housing removal.
F '
SOCKET WRgNCH a w .
\ -. AhdT '	x-'.	< ...'	,,“d. I
■ z *
h( SCREW, CAP - SM-40071* WASH», lOCK - BKXa	SCREW, CAP - HM.40070A WASHER, IQCK - 8K»M RA PD 8073
Figure 135.—Crankshaft removal.
208
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HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS 43
DOWELS HM-I7O7A^Z------*------“---7------OtL HOLES ——
■ gMIR y	KIBKF GEAR. HM-22t»9B J
\	wV	>	W-"* "W KEY - BCAX5CC
BOLTS - HM-ZZlWt	CRANKSHAFT HM-4$85jO
RA FC 8075
----DOWEL - HM-4&42A
Figure 136.—Crankshaft.
.a <	»
•A
, i
SHELLS. IhUERMEDlATE X	MSbC SHElL’ 8£ARiN6>
BEARING-HM-4571 IB *	. CENTER - HM-457098
?, icj* r
•	'LgW ■*	1 I
■4/	M*-* i	M
Hi	- »	;
'/y!' p ■-v '
 
- - . :
EAR OR PROJECTION	SHELLS REMOVED
’W::: ■ ■	RA FS> 8074
Figure 137.—Main bearing shell removal.
476794	42----14
209
TM 9-1706
43
ORDNANCE MAINTENANCE
Ilk
I	r
± ■
JMHH&
PILOT BAR ...	jfe~
'■/Scf ''
.. ,
.	' .■ , -,a£X	'
'
'	Wife
. Si	v *' c. ?.
' B
? | ’7 *w«£ /	. p	G WE, TAPPET -
|	'U	!■	^<-^' HM-22089A
If® B w ®Wff ■<
■BsWWa,1 *JML- w Z <
■Hr VHHr
i
^7	/ i? y
I RA PD 8055
Figure 138.—Valve tappet guide removal.
210
TM 9-1706
HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS 44
44.	Maintenance and repairs.—a. Cleaning.—After the engine has been thoroughly disassembled, all component parts should be thoroughly cleaned of oil, grease, and carbon prior to inspection. The cleaning is done in the following manner:
(1)	Soak all aluminum parts overnight in cleaner, engine solution. Rinse the parts in hot water and dry them.
(2)	Clean the pistons as explained above and clean the ring grooves with a broken piston ring ground flat on the end.
(3)	Place all steel parts in cleaner, engine solution. Leave them long enough to dissolve all grease and dirt. Remove the parts, rinse in hot water, blow out with compressed air from an air hose, and wipe dry.
Note.—Never immerse an aluminum alloy part in a steel stripping solution, regardless of how weak the solution may be. It may be necessary under certain circumstances to further clean steel parts such as valve heads, piston pins, shafts, etc., by buffing on a wire wheel.
(4)	Cylinder block and crankshaft oil passages should be cleaned thoroughly by forcing steam through each opening until it flows without restriction.
(5)	Strip off all gaskets and clean all surfaces where sealing compound has been used by scraping and washing with a suitable solvent.
1). Inspection.—After parts are cleaned as explained above, each part should be inspected and then covered to protect it from dust and dirt, etc., if it is to be used for reassembly. Set all discarded parts to one side and mark in such a manner that they will not become mixed with the new parts intended for replacement when the engine is reassembled. When out-of-round, taper, or wear exceeds limit values specified (see d below), a new part or a permissible reworking of an old part to the standard of oversize or undersize is the only remedy— except complete replacement of the part or parts. If available, the magna-flux inspection process should be applied to all steel parts except ball and roller bearings, studs, standard nuts, and washer.
(1)	Bushings.—Loose, damaged, or worn bushings must be removed and new ones installed.
(2)	Studs.—Any loose, broken, or damaged stud, or any stud that has been turned until it does not have proper height above its flange must be removed and a 0.003-inch oversize stud installed.
(3)	Cylinder block and crankcase.— (a) Check block for cracks.
fib) Check top surface for squareness, and reface if necessary.
(c) Inspect all expansion plugs and remove loose or damaged plugs. Replace with new plugs.
211
TM 9-1706
44
ORDNANCE MAINTENANCE
() Place a small amount of compound, valve-grinding, fine, around the face.
(c) Rotate valve back and forth with a hand or electric valvegrinding tool until a finished surface is secured (fig. 148).
(cZ) Remove valve and clean compound from valve and valve seat.
(tf) Test valve for perfect contact with seat in cylinder head by marking lines about % inch apart on face of valve with a lead pencil. Insert valve in guide and give a one-half turn to the right and a one-half turn to the left. If all pencil marks are removed, the operation may be considered satisfactory. If, on the other hand, one or more pencil marks remain untouched, the valve or seat should be reground or lapped until it seats properly.
219
RA PO 8057 REAMING TOOL	2" X 45° CUTTER VALVE SEAT
Figure 145.—Valve seat reaming.
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44
ORDNANCE MAINTENANCE
(10)	Flywheel ring gear replacement.—If inspection indicates that a new ring gear is required, it should be replaced as follows:
(«) Saw through and knock off old ring gear.
(&)	Heat new ring gear so that it will fit into position on flywheel and allow it to cool (shrink it).
d. Service data.—See paragraph 75.
220
RA PD 8122
Figure 146.—Valve seat checking.
TM 9-1706
HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS 44
Figure 147.—Valve refacing.
221
TM 9-1706
44
ORDNANCE MAINTENANCE
W.
WBim .-'- ' '	' " '"	i '> s
| T 9jhv
I J\
V
3**1110* "* «
■ ■’ S ■ .
vfe
SCREWDRIVER —►
VALVE
™.	•	«, j£ ' IS /	SPRINC.ON '
i»>*Y '_________V*‘'M'W
 
r •	• i
-■>.	I = '■■	■
&aMu r 9	\ M ro S059
Figure 148.—Valve grinding.
222
TM 9-1706
HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS 45
45. Assembly.—Tools:
Press.
Wood blocks.
%-inch socket wrench.
%-inch socket wrench.
Speed handle.
Tension-indicating wrench.
Long pry bar.
2-inch open end wrench.
%6-inch socket wrench.
Screw driver.
%-inch open end wrench.
Hammer.
Pinch bar.
Brass drift.
Ball peen hammer.
Diagonal pliers.
6-inch ratchet extension. 0.003-inch ribbon feeler with eye. Small hand scale.
Vise.
Feeler gage.
No. 000 emery cloth.
Filing fixture.
Ring expander.
Piston ring compressor.
Valve spring lifter.
2%-i n c h ope n-e nd tappet wrenches.
%6-inch open end wrench.
Spark plug wrench.
%-inch open end wrench.
%-inch open end wrench.
a.	Replace, crankshaft timing Press.
gear.	Wood blocks.
Set Woodruff key in position on shaft and press timing gear onto shaft over key. Make certain that timing punch mark faces outward.
b.	Replace crankshaft and main %-inch socket wrench. bearing shells.	%-inch socket wrench.
Speed handle.
Check crankshaft bearing on shaft while shaft is still out of vehicle so that piston drag will not be included. Then place new upper bearing shells in position in crankcase and lubricate. These bearing shells are locked against rotation by means of a small projection on each shell. Be sure these are in proper position. Position crankshaft in crankcase and lubricate. Replace bearing caps after they have been properly fitted with new bearing shells and three brass shims (0.003 inch each) have been placed in position on each side of bearing. The main bearing caps are numbered 1 to 7, inclusive, beginning with front bearing cap as No. 1. Be sure to replace them with numbered side of cap toward camshaft. Replace lock washers and cap screws but do not tighten (fig. 149).
223
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45
ORDNANCE MAINTENANCE
DOWEL, CAP, BEARING, DOWELED - HM-40541B
FLYWHEEL- /
HM-1707A	/ SCREW, CAP-HM-40071A
washer, lock - becxil
_	......fct |M|	_
>	AS
■	4sWw 'M 4 WsfliOMVi
i .	«...	.
1	’	....... ,;. ■ yi f
W
I w .	•	“ t* . ’&/	>	.	4
: ■ . ■ ' ' - : = !
'7
*
SHIM, CENTER AND REAR BEARING - HM-40551A
-- DOWEL, FLYWHEEL ALIGNING - HM-4642A	RA PD 8076
Figure 149.—Crankshaft replacement.
224
TM 9-1706
HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS 45
c.	Adjust crankshaft bearings. Tension-indicating wrench. Long pry bar.
Adjust bearings one at a time. To adjust each bearing, remove or add equal amounts of shims to each side until shaft can be turned only by considerable effort when cap is' drawn down tight (see par. 44;	A- .< i X * ,fc W .# hw ip
■®:	.	;	। < I ;	'	<	'	■ ■
■r ’ •■ it - fw i tlZZl a uJw -1 .	.	-	I	■	■	■
IlBW	W WWxM
■ ■	■ "' ■"'■'■ ': .. ■ ■■ ■ ' ' ■-•
1 .
I	•, *	i .’	I ,	' 1
I „ ..^	■
MWM»	-z '
y?.:	■ x ’
RA PD 807rtiHHHi
Figure 150.—Main bearing cap tightening.
ROD, VALVE PUSH, A^iMM,Y—HM-45812-ASY
“ H	*
'y	। •
^■> ■■. .
ROD-HM-458I2A	, •	SCREW—HM-2185A
|^.... j mA
i;J	' '	/	-
f	NUT-HM-21MA . RA
Figure 151.—Valve tappet (or push rod) group details.
226
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HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS 45
w	GEAR, CRANKSHAFT -
VALVE TIMING PUNCH MARKS	„ ovn'iQR
GEAR, CAMSHAFT-HM-22049B	,	jCH
• GEAR, IDLER ASSEMBLY -\<**^**^	Wkz .MB*
„•£" .	*s4»/
,.JJk •. ■........- <
$ i
........ ■
Figure 152.—Camshaft ami idler gear replacement.
227
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45
ORDNANCE MAINTENANCE
Figure 153.—Crankshaft oil seal replacement.
A — SCREW - HM-1 4595A
B — NUT - BBCXID
C—PLUG - HM-1 4591A (FIBER BUTTON)
D—GEAR COVER
E—STEEL PLUG IN SHAFT
F — NUT - HM-1 I023A
(HM-2045A
G —THRUST WASHER LjCAMSHAFT)
IHM-4024A
I (WATER PUMP)
RA PD 10908
Figure 154.—Shaft end play adjustment.
228
SEAL. OIL HM-11137 AS /
FELT SIDE OUT--
TM 9-1706
HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS 45
i.	Check camshaft and idler Screw driver.
shaft end play.	%-inch open end wrench.
The end play of the shafts is controlled by special adjusting screws and lock nuts through gear cover (fig. 154). Loosen lock nut for each screw in turn and tighten screw with a light pressure by hand or with screw driver. Then back off screw one-eighth turn and tighten lock nut.
Note.—Water pump shaft end play should be adjusted in the same manner at installation.
j.	Install fan drive pulley. Hammer.
Place trunnion in position on timing gear cover (fig. 155). Then set Woodruff key in place on crankshaft, line up pulley key way with key, and drive pulley onto shaft. Replace special lock washer (fig. 156).
k.	Install starting crank jaw. Pinch bar.
Hammer (handle).
011
AfeMfr da
FITTING-ODX5K	‘ Ifck
"v.
X	' Wy .............
TRUNNION, FRONT-
M	‘	WI-3487I2 (SCA)
RA P0 SORT	W	WI-363728 (SCB>
Figure 155.—Front trunnion installation.
Place special lock washer on shaft. Place hammer handle between one crank throw or crankshaft and bottom of cylinder block to pre
229
TM 9-1706
45
ORDNANCE. MAINTENANCE
vent crankshaft from turning. Then place pinch bar in hole in crank jaw and screw crank jaw tight on shaft.
I. Replace engine bell housing Brass drift (or special driving oil seal.	tool).
Drive new oil seal into engine bell housing as shown in figure 157.
m. Install engine bell housing. 3^-inch open end wrench.
-y It
I
Ki /	fit
'"'.?	■ '.	' '■"'	.	■..••;	'T-
v	?W fVr*	'
■•■ V	f X V •Tv
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N	/
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-	'	' "	’ -	^\	Kt¥ SLOT
PULLEY-.HM-45493B xx	\
K6Y-BGAXM	WA5HEB-HM-U734A
RA P^8088
Figure 156.—Fan drive pulley installation.
Shellac new gasket to front of bell housing. Attach bell housing to crankcase with lock washers and cap screws. Check clearance between oil seal and crankshaft flange (fig. 158). (See par. 44d for correct clearance.)
n. Install flywheel.	Ball peen hammer.
Wood block.
Diagonal pliers.
%-inch socket wrench.
6-inch extension.
Long handle.
230
TM 9-1706
HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS 45
Drive large dowels into crankshaft flange. Set flywheel on studs and dowels and drive into position. Anchor crankshaft with wooden handle of hammer. Set castle nuts on flange studs, turn them up tight, and replace cotter pins. Place new expansion plugs in large dowel holes and secure by tapping the center with ball peen hammer. Drive clutch pilot bearing into flywheel (fig. 159). Remove hammer.
C	» DRIFT SEAL, Oil - HM-3543A
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...
<■	..	'j£	j. ■
AY, .,	'	, IBS , -/'&Z
?	>YA >	\
/	5 TIMING HOLE
SELL HOUSING - HM-24427D	' U	RA f>£> SO85
Figure 157.- Bell housing oil seal replacement.
231
TM 9—1706
45
ORDNANCE MAINTENANCE
/I	FEELER gauge
*v<\X %" -x -4 * xC^sz '"'' % ’""' z -	'^X, /
^T
•■»«*■•■• #	■'■,-—•«•. zC- *•<	"•
■
i ' Bw I	:
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. 1
BRACKET- ' . J ’ ' (A • ^■HTxJI/ O
WI-344927(LH.)
WI-311969(R.H.) -.\^
SCREW, CAP - BCAXIEE \ WRfc %	V ■ '
WASHER., LOCK - BECXIM \	f ’, \..
'	■ .	RA PC 8086
___	SCREW, CAP-BCAXIEC - WASHER. LOCK-BECXIM
Figure 158.-—Bell housing replacement.
232
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HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS 45
SOFT METAL OR WOOD BLOCK BEARING, PILOT- FED-8025
Ww ■,	A
' ■
Ir • k	>
r	^g i
>	gdflF *
X ^WSPU G	ra PB 8(JSo
Figure 159.—Flywheel installation.
o. Fit each piston to cylinder 0.003-inch ribbon feeler with eye. bores.	Small hand scale.
Place ribbon feeler between cylinder bore and inverted piston as shown in figure 160. When ribbon feeler can be pulled out by hand with a “slight drag”, the fit is correct. If a scale is used on end of ribbon feeler, the pull exerted to remove gage should read 8 to 12 pounds on scale.
p. Install piston pins.	%6-inch socket wrench.
Vise.
Fit piston pins to pistons to a hand-push fit at room temperature (70° F.). Set connecting rod in piston so that number on rod is opposite split side of piston. Install pin through piston and rod so that notch in pin lines up with clamp screw hole in rod to prevent damage to threads of clamp screw while screw is being installed. Replace and tighten clamp screw. The piston pin fit may be checked, after rod has been assembled, by holding piston with pin horizontal. The weight of the rod should be not quite sufficient to
233
TM 9-1706
45
ORDNANCE MAINTENANCE
turn pin in piston (fig. 161).
proper alinement (fig. 162).
q. Fit rings to pistons.
All rings should be true and j fit each in its respective groove.
Check piston and rod assembly for
Feeler gage.
No. 000 emery cloth.
ist wide enough to be a light “rolling”
If ring fit is correct, ring should re-
EYE
r,b8on	o
FEELER	j|k
■ PISTON (INVERTED)	\ l||g.
HM-40120C	g "
\	zW	.	.
\ 1
1	vw* *H,7Z
K ‘ SBB , '	#''■ ‘ *
' ZJ .	»; • ’ >< • i'S
w	WW
>•	a,:'1OSIfeS!Ss?a3B|
%	w
■HHHHHHHHHHHMIIHMHHHHHHHHFa p°8090
Figure 160.—Piston fitting to cylinder bore.
main suspended in groove as shown in figure 163. If ring is too wide, reduce its width by lapping on a sheet of No. 000 emery cloth placed on a flat surface. (See par. 44
4	•£ fc	wXSl;? ' |L ' y). 'X‘ , <* *	~"- jC
f jk, ■/	oCgyj	'
,i '	W	Jt	*	Si
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n ; C w 'y *	'	' /A f. * HI
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r /
iC i	. -	■ ■
3 / I	?>
< / "*W £g^ M «|	< 1 Apt	«
p /	(
I "4 .
,/'(	XI t It	N: ;
«I -z.	'1! t	
.. WSK-K^w-^ S'. ' y	I 75
o» r'	.	; .>	;
'"^ *
~-'^T^wMimr wy-	L. r'
;	5
Stwc feSx *-4*C^WfeiX' X-
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«» x 'I' p-
S Z*' ' ’ v<
£	vW 4	5:?L t? J
2E G	i
X >'	3	.. ;t-/X,-> -'-' s,
2 « gd, •	’
. Z g ® ' at	«i	m
■-"• r* •
§	"T’
d.	. WK	t .
Figure 170.—Cylinder head replacement.
244
TM 9-1706
HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS 46
■’■$ i . ■
-••■: :jin..,-
x 8 4c z ■£’ .^^.’^^SSSSSZi^ 3? gL^ ■*
"IB pg V;.
JI Ely •:-X^J| If
CAP—HM-40038AS	f > #
r	& 1
SCREW, CAP—8CAX3B	V<-’ jZj "
WASHER—HM-8191A
WASHER, LOCK—BECXIH
CLIP—HM-45842A	t '
B '* 1
PIPE—HM-45535“--"“^ H	lli&ZJw 'CW'-'ZZ S ™
lliZ xl .
TAP HERE	>Z * ‘	. /---,'x
*
EASY DRIVING---..	£.,.
m Z,- i k
Wl	. «R ■ ■* -4/ ’ ~ ) /<
-
4	it
r	■»
f g
f	■ ra pd 8ioz
Figure 171.—Oil filler and breather pipe replacement.
245
TM 9-1706
46
ORDNANCE MAINTENANCE
a.	Install clutch assembly. %6-inch socket wrench.
Clutch pilot bar.
Lubricate clutch pilot bearing. Hold driven member in position and insert pilot through assembly into pilot bearing to aline assembly (fig. 172). Secure cover plate to flywheel by replacing lock washers and cap screws (fig. 173). Tighten cap screws evenly to prevent distortion of cover plate.
b.	Install starting motor as- %6-inch open end wrench. sembly.
% J
-^z-.	Mix <- i	'
CLUTCH DiSC «	‘
' jt -TBSl	A »Nr. x
I f ff'	-.
. _.	\
axBl F mF"	; w	AA
I	c.e x, A-	Y	fil
w £ Jj ® I	i i s> i 1
Ax'W' ! *
A * x j^ w£*xi j . J f piotba«-	. ,	< y- . : a
,:« J «
w
■%\ ■ '	; NIPPLE -Wl-380167
■ t " C O	:	UNION-WI-V252IX
■ ’ • w-' -Zip fl	a-iWabMpiPE>ASS'Y'Wl~346746
flMB Wr : X';u- /•	/;•:-••• .’ ’ •'	:■ uD-VJi-368565
'• 'I1'■>.	'NUT-BBBXID
:	8fcy	•'wtoW ’ I- —: tWASHER,LOCK“BECXIL
[GASKET-WI-A249I8X
;.	u	,.!W„. . [INSULATOR ' Wr 363727
CLEANER,ASS’Y-UA-T-175-9497
;'	• •;	J- »-	PSCREW.CAP- BCBXICA
. aassa^a j-jut-bbbxic
*'	W •washer,lock-becx!k
CUP,ASS’Y-WI-357067
ra pd 326i
Figure 174.—Fuel system, installed.
255
TM 9-1706
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ORDNANCE MAINTENANCE
b.	Fast idling.
(1)	Carburetor throttle controls sticking.
(2)	Carburetor throttle setting.
c.	Low fuel pressure.
(1)	Fuel pump diaphragm not operating properly.
(2)	Diaphragm punctured.
(3)	Air leaks in system.
d.	Lack of fuel at carburetor.
(1)	Empty fuel tank.
(2)	Broken fuel pump diaphragm.
(3)	Fuel leaks.
(4)	Sticking carburetor float valve.
(5)	Loose fuel pump cover plate screw.
(1) Free controls.
(2) Adjust throttle stop screw and reset idling screw.
(1)	Tighten holding screw.
(2)	Replace diaphragm.
(3)	Tighten connections.
(1)	Fill tank with fuel.
(2)	Replace diaphragm.
(3)	Check lines, tanks, etc.
(4)	Replace valve and seat.
(5)	Tighten, and replace gasket if necessary.
51. Carburetor air cleaner.—a. Description (fi[r. 175).—The carburetor air cleaner is of the oil bath type and is mounted on the dash at the right rear of the engine compartment.
(1)	Construction.—The carburetor air cleaner consists of two cylindrical sheet metal sleeves, one inside of the other, with an airspace between the inner and outer sleeves. The inner adapter sleeve contains the air filter hair, the air outlet elbow at the top, and a baffle plate attached to the bottom. The inner sleeve is beaded in four places to center and attach the outer sleeve. The oil bath (reservoir) cup slides over the lower portion of the outer sleeve and is held in position by two thumb screws.
(2)	Functioning.—The dust-laden air, entering around the space between the inner and outer sleeves in a rotary motion, forces a large part of the grit and dust to deposit on the walls. Additional dust is washed out when the air comes in contact with the oil bath. The semiclean air is thoroughly filtered while passing through the hair filter element, which is kept moist by the splash of the agitated oil bath. Clean air proceeds to the carburetor intake while the dust is washed into the sump.
256
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HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS 51
CLEAN AIR TO CARBURETOR
DUST LADEN AIR
.V
AIR INTAKE AROUND ENTIRE CLEANER
FILTER ELEMENT IN WHICH CONTINUOUS WASH OF OIL REMOVES THE REMAINDER OF DUST
OIL SPRAY IN AIR STREAM
BEAD INDICATING PROPER OIL LEVEL
LARGE PERCENTAGE OF DUST STRIKES OIL AND IS REMOVED AT THIS POINT
OILRESEVOIR INTO WHICH DUST IS WASHED
A BAFFLE TO PREVENT EXCESSIVE AMOUNT
■***^^- OF OIL BEING
DIRT DEPOSIT DRAWN INTO FILTER AT HIGH MOTOR SPEEDS

RA PD 33314
Figure 175.—Air cleaner assembly, sectionalized.
(3)	Specifications.
Make_______________________________
Type-------------------------------
Ordnance No________________________
Manufacturer’s No__________________
White No___________________________
United Specialties Co.
Oil bath.
B167665.
VA-T175-9497. 347323.
b. Trouble shooting.—See paragraph 526. c. Removal.—Tools:
i/j-inch open end wrench. Screw driver.
%6’inch open end wrench.
(1) Remove carburetor air i^-inch open end wrench. horn and rubber hose assembly. Screw driver.
Loosen clamp holding hose to air cleaner outlet. Then loosen cap screw holding air horn to carburetor air inlet. Lift horn from carburetor and remove horn and hose assembly (fig. 176).
476794°—42 —17
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ORDNANCE MAINTENANCE
(2) Remove air cleaner.	%6-inch open end wrench.
Take off four hex head nuts and lock washers from bolts that attach air cleaner to dash and remove cleaner.
d. Disassembly.—Tools:
%-inch open end wrench.
Screw driver.
(1) Remove oil bath cup. None.
Loosen two thumb screws and remove cup from outer sleeve.
(2) Remove air baffle plate. %-inch open end wrench.
Screw driver.
Remove four bolts, nuts, and lock washers from brackets and lift off baffle plate.
Figure 170.—Carburetor air horn and hose assembly removal.
e. Maintenance.— (1) All connections between air cleaner and carburetor should be inspected at frequent intervals and should be kept tight.
(2) The oil bath cup should be inspected daily and kept filled with engine oil to the oil level mark indicated on the cup. Do not remove oil cup while engine is running.
(3) The air cleaner cup should be cleaned thoroughly and refilled with used crankcase oil or the same oil that is used in the engine,
258
ITrA PD 10992 '
TM 9-1706
HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS 51-52
each time the crankcase is drained and refilled or at intervals of 1,000 miles.
(4) Every 2,000 miles the air cleaner should be removed from the dash and cleaned by washing in solvent, dry-cleaning, to remove the accumulation of dust and dirt from the hair filter element.
/. Assembly.—Tools:
%-inch open end wrench.
Screw driver.
(1) Install air baffle plate. %-inch open end wrench.
Screw driver.
Place baffle plate on brackets and secure with four bolts, nuts, and lock washers.
(2) Install oil bath cup.	None.
Slide cup m position over air cleaner outer sleeve and secure with two thumbscrews.
g. Installation.—Tools:
%6-inch open end wrench.
Screw driver.
(1) Install air cleaner on dash. %6-inch open end wrench.
Place air cleaner on dash so that the bolts come through the bracket holes, and secure assembly with four nuts and lock washers.
(2) Install carburetor air horn Screw driver. and hose assembly.
Slide air hose over cleaner outlet elbow and place air horn over carburetor air inlet. Tighten hose clamp at air cleaner and air horn clamp bolt at carburetor.
52. Carburetor.—a. Description (fig. 174).—The carburetor is a Zenith down-draft type. It is located at the right side of the engine and is bolted to the inlet manifold header flange. The choke and hand throttle control buttons are located on the instrument panel.
(1) Construction.—The carburetor is a down-draft unit of double venturi design. It is a balanced carburetor which maintains proper depression ratio between the air intake and the fuel bowl. Air cleaner restrictions have a minimum influence on mixture ratio. This construction protects bowl vent, well vent, idling air opening, etc., from admitting dirt, as all air must enter through the air cleaner. The carburetor choke valve is manually operated.
(2) Functioning (fig. 177).—(a) Idling system.—The carburetor idling system consists of the idling jet which measures the fuel and
259
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ORDNANCE MAINTENANCE
the idling adjusting screw which regulates the air. The idling system functions only at idling and speeds below 20 miles per hour. At these speeds the throttle valve is almost closed and there is a very strong suction past the edge of the throttle valve. The mixture of fuel and air from the idling jet is discharged through the priming plug.
(S) Compensating system.—The compensating system consists of the main discharge jet and the well vent. The flow of fuel from the main jet is controlled by the size of the well vent and the size of the main discharge jet.
(c) Main jet system.—All fuel for part throttle operation is supplied through the main jet orifice. The main fuel passes through the main discharge jet and into the air stream through the secondary venturi. The main jet is located in the fuel bowl. When manifold depression drops, the power jet system comes into operation to supply additional fuel for maximum power.
(d) Power jet system.—The power and accelerating system supplies the extra fuel required for maximum power and acceleration during the periods of low intake manifold vacuum that occur at wide open throttle and low engine speed, and momentarily when the throttle is opened quickly. This extra flow of fuel continues only as long as the manifold vacuum is low. As the vacuum increases the vacuum
piston assembly is drawn upward in its cylinder and the power jet valve closes, shutting off this extra fuel.
(3) Specifications.
Make____________________ Zenith.
Model------------------- 1%-inch down-draft Z-IN-167SJ.
Manufacturer’s No_______Z-O-9232.
White No________________ 347308.
Ordnance No_____________ B167753.
Weight------------------ 10% pounds.
b. Trouble shooting.
Symptoms and probable cause
Probable remedy
(1)	Rich mixture.
Carburetor choke not fully opening.
(2)	Engine dies.
Engine will not idle.
(3)	Fast idling.
(a) Improper control adjustment.
'(&) Carburetor throttle.
Free up valve shaft and lubricate. Adjust choke control.
Adjust idling screw.
(a) Adjust throttle control button and throttle stop screw.
(5) Free up shaft and linkage and lubricate.
260
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HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS 52
i	I WW y
IJL	1 r zOIAy U .
.»fr/a	* t—s
ji ^mU
■- - /b31Iw <£ I	WIIFj
°	* * I »* -a tir
JHr	wW (Si	a	Is
fill® Wf
» , j ^3w ®tII	ii ■■ n
RA RD 7388
(T) Zenith carburetor.	® Carburetor sectionalized.
A.	Check valve.	H.	Idling fuel channel.	Q.	Main jet.
B.	Bowl drain plug.	J.	Idling jet.	R.	Well vent. _
C.	Power jet valve.	K.	Idling air and fuel channel.	S.	Choke valve.
D.	Vacuum piston assembly.	L.	Power jet channel.	T.	Inlet fitting plug.
E.	Vacuum passage.	M. Priming plug.	U. Secondary venturi.
F.	Power jet.	N.	Main discharge jet plug.	V.	Venturi.
G.	Idling adjusting screw.	P.	Main discharge jet.	W.	Throttle valve.
Figure 177.^—-Carburetor assembly, sectionalized.
(c) Carburetor controls sticking.
(d) Air leaks.
(4) Lack of fuel.
(a) Empty fuel tank.
(c) Free up and lubricate.
(d) Check intake manifold and carburetor gasket. Tighten manifold and carburetor units.
(a) Refill tank with fuel.
261
TM 9-1706
52
ORDNANCE MAINTENANCE
(b) Bent or kinked tubing.
() Dirty air cleaner.
().
(3)	Remove air intake body %-inch open end wrench. assembly.
Remove three body attaching screws and lock washers and lift off air intake body and gasket (figs. 181(2) and 182).
(4)	Remove bowl float., axle, Screw driver.
and valve.
Spread slot in float bracket with screw driver and take out axle and float (fig. 181(a)) ; then lift float valve from seat.
(5)	Remove float valve seat. %-inch socket wrench.
Unscrew float valve seat and lift off fiber washer (fig. 181(4)).
(6)	Remove vacuum pump as- None.
sembly.
Lift out vacuum pump assembly by hand (fig. 182).
264
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HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS 52
Figure 179.-—Carburetor assembly removal.
265
.RAGPD 10994;
TM 9-1706
52
ORDNANCE MAINTENANCE
80 BC 88 BA	AZ	AY AX AW AY AU AT AS Aft AQ
-..—T \	"
W* O	, J	$_1	r2S»-AN
.— --------	r
V*N^R^ .*
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1 *	/T% t-
! I / i H °\7® I I	11.	r
L M N P " Q RSTU *WF' V w	X Y z AA AB AC	RA po
Figure 180.—Carburetor assembly, exploded view.
266
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HERCULES JXD
GASOLINE ENGINE FOR SCOUT CARS
52
267
A.	Pump assembly—Z—C36—11.	Y. Washer—Z-T56-24.	AX. Pin, cotter—Z-T61-4.
B.	Valve assembly—-Z-C97-10.	Z. Body, assembly—Z-Al—8K-3.	(Screw, cap—Z-T8S31-14.
C.	Plug—Z-CT91—1.	AA. Float, assembly-—Z-C85—54.	qWasher, lock—Z-T43—103.
D.	Plug—Z—C138—23.	AB. Axle—Z-C120-26.	AZ. Gasket—Z-C142-25.
E.	Washer—Z-T56-23.	AC. Bracket—Z-CR88-2.	BA.Jet (idling)—Z-C55-11.
F.	Jet (main discharge)—Z-C66-	AD.	Valve, assembly-—Z-C81—3.	BB.	Vent—Z-C77—14.
23-1.	AE.	Washer—Z-T56-23.	BC.	Valve—Z-C41-9.
G.	Screw—Z-T8S10—15.	AF.	Screw, drive—Z-T73-15.	„	(Jet (main)— Z-C52-7.
H.	Spring—Z—Clll-62.	p (Screw—Z-C138-61.	4 Washer—Z-T56-24.
J.	Pin, taper—Z-CT63-5.	Washer—Z-T56-5.	BE. Screw—Z-T8S8-6.
K.	Screw—Z-T8S10-9.	AH. Washer—Z-T56-36.	BF. Lever, assembly—Z-C24-
L.	Lever—Z-C24-10X8.	AJ. Body—Z-C148-10A.	138X5.
M.	Lever—Z-CR28-19X5.	AK.	Washer—Z-T56-15.	BG.	Screw—Z-T8S25-10.
N.	Packing—Z-CT57-2.	AL.	Plug—Z-C149-22.	BH.	Stop, assembly—Z C25 98X5.
P.	Plate—Z-C21-5.	AM.	Screw—Z-C136-3.	BJ.	Bushing—Z-CR9-5.
Q.	Screw—Z-C136-12.	AN.	Shaft, assembly—Z-C105- BK.	Pin—Z-CR121—20.
R.	Cap—Z-C116-11.	102.	BL. Venturi (secondary), assem-
S.	Pin, cotter—Z-T61-5.	AP. Collar—Z-C130-4.	bly—Z-C39-12.
T.	Shaft—Z-C23-4.	AQ.	Pin, taper—Z-CT-63.	BM.	Screw—Z-C46-6.
U.	Intake assembly—Z-B4-19.	AR.	Shutter—Z-C102.	BN.	Spring—Z-Clll-17.
(Screw set—Z-T1S8-7.	AS.	Screw—Z-T1S8-10.	BP.	Retainer—Z-CR115-10.
^Washer, lock—Z-T41-8.	AT.	Bracket—Z-C109-7X7.	BQ.	Spring—Z-Clll-27.
W. Venturi—Z—C38—37.	AU.	Screw—Z-CT4S10-8.	BR.	Bushing—Z-CR26-61.
X. Jet (Power and accelerating)— AV.	Lever assembly — Z-CR106— BS.	Screw—Z—T8S8-7.
Z-C57-1X4.	107.	BT. Screen—Z-C150-1.
AW. Screw -Z-T8S8-10.
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52
ORDNANCE MAINTENANCE.
® Carburetor fuel inlet union removal. © Carburetor needle valve seat removal.
screw with spring removal.
© Carburetor float removal.	© Carburetor power and accel-
erating jet removal.
Figure 181.—Carburetor disassembly.
208
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HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS 53
F 6 ®.
e
c 0	* |k
‘ * irwr ¥*F-
■s<7yW|
v® < > W WW1	sU fc/ < /
*w " w*E.J Hk t»	/
K	’ ’d®
W F a ’	*■	s
RA PD 33307	"vfe‘ " : 1 ’ '.•-
A.	Secondary venturi.	E. Float.
B.	Well vent.	F. Power and accelerating jet.
C.	Idling yent.	G. Air intake.
D.	Vacuum piston assembly.	H. Float needle valve and seat assembly.
Figure 182.—Carburetor air intake removal.
(7)	Remove idling adjusting Screw driver.
screw, with spring.
Unscrew idling adjusting screw and remove the screw and spring (fig. 181@).
(8)	Remove float valve fuel Screw driver.
passage plug.
Unscrew and remove float fuel passage plug and fiber washer.
(9)	Remove power and acceler- Zenith tool No. Z-C-161-82 ating jet.
Unscrew and remove power and accelerating jet and washer (fig. 181©).
(10)	Remove choke valve shaft Small punch.
thrust collar.	Hammer.
Drive out taper pin and remove thrust collar from shaft (fig. 183®).
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52	ORDNANCE MAINTENANCE
(11)	Remove choke valve limit- Pliers. ing spring and retainer.
Pull cotter pin that locks limiting spring retainer to shaft and slide retainer and limiting spring from shaft (fig. 183©).
(12)	Remove choke valve lever Screw driver. and lever bushing.
Loosen choke valve lever clamping screw and remove lever from bushing and bushing from shaft (fig. 183©).
(13)	Remove choke control Screw driver. bracket.
Loosen tube holder bracket clamping screw and remove bracket (fig. 183©).
(14)	Remove choke valve and Screw driver. shaft.
Remove two screws that attach choke valve to shaft. Then pull out choke valve from slot in shaft and slide out shaft.
(15)	Remove main discharge %-inch open end wrench.
jet.	Zenith tool No. Z-CM 61-82
(equivalent tool).
Screw driver.
Remove main discharge jet plug and washer (fig. 183@). Then unscrew main discharge jet and turn body over and jet will fall from hole (fig. 183©).
(16)	Remove power jet check Screw driver. valve and main jet.
Unscrew power jet check valve and main jet and turn carburetor body over to allow valve jet and washer to drop from holes.
(17)	Remove power jet valve. Zenith tool No. Z-C-161-81.
Unscrew power jet valve and turn carburetor body over to allow valve to drop from vacuum piston hole (fig. 183©).
(18)	Remove well vent and Zenith tool No. Z-C-161-80 (or idling jet.	%6-inch open end wrench).
Screw driver.
Unscrew and remove well vent and idling jets from their seat (fig. 182).
(19)	Remove venturi.	Screw driver.
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© Carburetor choke lever assembly.
@ Carburetor pump check valve and main jet removal.
® Carburetor main discharge jet plu: removal.
@ Carburetor power jet valve removal.
© Carburetor main discharge jet © Carburetor venturi removal, removal.
Figure 183.—Carburetor disassembly.
27.1.
I PUMP 'CHECK VALVE
' A A ■-
' X’
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52	ORDNANCE MAINTENANCE
Remove venturi locking screw and lock washer and pull out venturi (fig. 183©).
(20)	Remove throttle valve. Screw driver.
File burs from throttle valve retaining screws (fig. 184©) and remove screws. Then pull out throttle valve from slot in shaft (fig. 184©).
(21)	Remove throttle valve Pliers.
shaft.	Drift.
Pull cotter pin from thrust cap and pull off cap and packing from shaft. Tap out shaft assembly (fig. 184@).
(22)	Remove throttle stop screw Screw driver.
and spring.
Unscrew throttle stop screw from throttle stop lever and lift off spring.
(23)	Remove throttle valve con- Screw driver.
trot loose lever and lever stop.
Loosen clamping screw on throttle control loose lever stop and slide both the stop and lever from the shaft.
(24)	Remove throttle control Screw driver.
rod lever.
Loosen lever clamping screw and pull off lever from shaft.
(25)	Remove throttle stop Small drift.
lever.	Hammer.
Drive taper pin from throttle stop lever and remove lever and packing from shaft.
e. 0arburetor maintenance.—(1) Inspection.—The carburetor should be removed, disassembled, and thoroughly cleaned in solvent, dry-cleaning, at least once a year or every 15,000 miles and the following inspections made:
(a) Inspect power accelerating jet, valve, and check valve for proper seating and replace if valves are worn and leaking.
(&) Check all jet orifices with proper size drills. If oversize due to wear, replace with new jets. When replacing jets make sure new jets have the same calibration numbers as the old.
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© Removing bur from throttle valve screw.
® Carburetor float removal.
® Carburetor air intake body removal. Figure 184.—Carburetor throttle shaft removal.
(c) Inspect float for dents and leaks and float hanger pin for wear. Replace if necessary.
(tZ) Examine float needle valve and seat. If needle shows a groove on the seating surface, replace both needle valve and seat.
(e) Inspect vacuum piston assembly as to fit in cylinder. If worn and loose in cylinder, replace complete piston assembly.
476794°—42---18
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(2) Adjustments.— (a) Uniform idling and part throttle operation are very much dependent on the location of the priming plug hole in relation to the throttle plate. For this reason throttle plates and bodies cannot be interchanged indiscriminately. If it is necessary to replace the throttle shaft or plate, back off throttle stop screw so that throttle plate can be completely closed. Holding the throttle in the closed position, scribe a line on the inside of the throttle body along the line of the throttle plate (fig. 185). Using the scribed line
Figure 185.—Carburetor throttle valve maintenance.
as a guide, replace throttle shaft or plate. If new plate shows a noticeable variation from the old one, select another new plate to get one that fits very close to the scribed line when installed.
(ft) All carburetor adjustments except idling are fixed, and for this reason the carburetor should not give any trouble, provided the regular cleaning and inspection periods are not neglected. However, carburetor jets will wear in service, resulting in an overrich mixture and lack of engine efficiency. Then replacement or overhaul is desirable.
(c) Correct fuel level height is particularly important in obtaining greatest fuel economy. This level may be checked with a conventional fuel level gage or by removing cover assembly and measuring the
274
RA RD 8015
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HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS 52
S T
it
J/ts tttJr
w v
d^	F —THROTTLE CONTROL WIRE
II	Ms©-	FLEXIBLE HOUSING CLAMP
A	^i-M©©Nx/K	BRACKET
G---%----A—BELLCRANK	G — CHOKE CONTROL WIRE
y^T'd-	B — BELLCRANK ROD	FLEXIBLE HOUSING CLAMP
F-----“MVIfM-----------------L	C ~ CR0SS SHAFT LEVERS H - CHOKE CONTROL WIRE
\	D — CROSS SHAFT BRACKET	CLAMPING SCREW
\	\	E — THROTTLE CONTROL WIRE J — CARBURETOR
Vm®-----M yuX p	CLAMP SCREW	K — ROD END BALL JOINT ASS'Y
E----»Jr	Y\\	L — THROTTLE VALVE SHAFT
jL	V\F71	M —THROTTLE VALVE SHAFT
TK	Th	N — THROTTLE ROD
____KJk	P —THROTTLE RETURN SPRING 1___\©|||^©	Q — ACCELERATOR PEDAL ROD
B xS>*-----C----*	R — ACCELERATOR PEDAL
S ~CH0KE CONTROL
A	T — LOCKWASHER
OF	■	U — CONTROL BUTTON
Q	R —v — L°CK NUT
w — THROTTLE CONTROL
RA PD 753 J
Figure 186.—Carburetor control linkage.
275
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52
ORDNANCE MAINTENANCE
height of the float. The float arm may be bent to obtain the proper adjustment. Set float with depth gage so that the distance from bottom of float to face of cover casting is 2%6 inches (fig. 186).
(d) Service data.—Venturi and jet sizes for Zenith model Z-IN-167SJ carburetor.
Main venturi No. 341.
Idling jet No. 131.
Main discharge jet No. 75.
Well vent No. 20.
Main jet No. 29.
Power and accelerating jet No. 24.
Power jet valve No. 20.
Needle valve seat No. 45.
Carburetor reassembly.—Tool, Screw driver.
Hammer.
Pliers.
Zenith tool No. Z-C-161-82 (equivalent screw driver).
%-inch open end wrench.
Zenith tool No. Z-C-161-81.
(1) Install throttle stop lever.
Replace throttle stop screw and on throttle shaft, lining up taper taper pin.
(2) Install throttle rod control lever.
Zenith tool No. Z-C-161-80 (or %6-inch open end wrench).
Zenith tool No. Z-C-161-25. 1l/i6-inch open end wrench. %-inch socket wrench. % 6-inch open end wrench.
Small hammer.
spring on stop lever. Place lever pin hole. Insert and drive home
Screw driver.
Place throttle control rod lever on hub of throttle stop lever and tighten throttle rod lever clamping screws.
(3)	Install throttle valve con- Screw driver trol loose lever and lever stop.
Place control lever in lever stop and replace both lever and stop on end of throttle shaft. Then tighten lever stop clamping screw.
(4)	Install throttle valve shaft Screw driver.
and throttle valve.	Hammer.
Insert throttle valve shaft into housing and slide throttle valve in shaft slot, lining up the screw holes (fig. 184@). Then screw in three throttle valve retaining screws and peen cover ends of screws.
(5)	Install throttle shaft cap Pliers. and packing.
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Place packing in throttle shaft cap and slide on shaft. Then insert and spread cotter pin.
(6)	Install venturi.	Screw driver.
Place venturi in position in body, lining up lock screw hole with hole in body, and secure with locking screw and lock washer (fig. 183®).
(7)	Replace main discharge jet Zenith tool No. Z-C-161-82 (equiv-and plug.	alent screw driver).
%-inch open end wrench.
Insert main discharge jet in hole and screw jet down against shoulder (fig. 183®). Place gasket on main discharge jet plug and replace plug in jet hole (fig. 183@).
(8)	Install main jet and power Screw driver. jet check valves.
Place main jet with gasket and power jet check valve in their respective holes in bottom of bowl and screw them down to their shoulders (fig. 183®).
(9)	Install poxver jet valve. Zenith tool No. Z-C-161-81.
Place power jet valve in hole in bottom of well and screw home (fig 183®).
(10)	Install idling jet and well Zenith tool No. Z-C-161-80 (or vent.	%6-inch open end wrench).
Screw driver.
Insert idling jet and well vent in their respective holes and screw down against shoulder (fig. 182).
(11)	Install float bowl drain Screw driver. plug.
Insert float bowl drain plug. Tighten with screw driver.
(12)	Install choke valve shaft Screw driver. and choke valve.
Replace choke valve shaft; slide choke valve in shaft slot, lining up the screw holes, and replace two choke valve retaining screws.
(13)	Install choke valve shaft Small hammer. thrust collar.
Place thrust collar on choke shaft; line up taper pin hole and insert and drive home taper pin (fig. 183®).
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ORDNANCE MAINTENANCE
52
TM 9-1706
(14)	Install choke valve control, Screwdriver. bracket.
Place choke valve control bracket on choke shaft boss and tighten clamping screw (fig. 183©).
(15)	Install choke valve lever Screw driver. and lever bushing.
Place lever bushing on choke valve shaft; place choke valve lever on bushing and tighten clamping screw (fig. 183©).
(16)	Install choke valve limit- Pliers. ing spring and spring retainer.
Slide choke valve limiting spring on shaft, inserting end of spring in bushing hole; place spring retainer on shaft, inserting other end of spring in retainer hole (fig. 183©). Exert tension on limiting spring by turning spring retainer clockwise three holes and then insert and spread cotter pin.
(17)	Install power and acceler- Zenith tool No. Z-C-161-25. ■ ating jet.
Place gasket on power and accelerating jet and insert jet and tighten (fig. 181©).
(18)	Install fl,oat valve fuel pas- Screw driver. sage, plug.
Place gasket on fuel passage plug and insert plug in hole below fuel inlet union.
(19)	Install float valve seat and %-inch socket wrench. float valve.
Screw float valve seat into body and drop float valve in seat (fig. 181@).
(20)	Install bowl float and Pliers. axle.
Hold float in position, lining up holes in float bracket with hole in hinge bracket, and insert float axle (fig. 182). Clamp axle to bracket by pinching slotted end of bracket.
(21)	Install air intake body. %-inch open end wrench.
Place new gasket between air intake body and main body and secure with cap screws and lock washers (figs. 181© and 182).
(22)	Install fuel inlet union as- 1%6-inch open end wrench. sembly.
278
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HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS 52
Place new gasket and screen on fuel union plug and insert plug in union body. Then place gasket between union and body and screw union plug into boss on top of bowl cover (fig. 181(T)).
(23)	Install idling adjusting Screw driver.
screw driver and spring.
Place spring on screw; screw all the way into seat and back off approximately three-fourths turn (fig. 181@).
(24)	Install carburetor fuel %6-inc“h open end wrench. filter.
Connect fuel filter assembly to carburetor fuel inlet union.
g. Carburetor installation.—Tools:
%-inch open end wrench. %6-inch open end wrench.
1/2-inch open end wrench. Pliers.
Screw driver.
(1)	Install carburetor.	%-inch open end wrench.
Using two new gaskets, one on each side of insulator, place insulator on inlet manifold flange. Place carburetor assembly in position on manifold studs and secure with stud nuts and lock washers.
(2)	Connect fuel line.	i^-inch open end wrench.
Connect fuel line from fuel pump to fuel filter inlet fitting with flared tube nut.
(3)	Connect throttle control. Screw driver.
Connect throttle control tube clip to bracket. Insert wire in throttle loose lever swivel hole and tighten wire clamping screw.
(4)	Install throttle control rod %6-inch open end wrench.
and return spring.	Pliers.
Connect throttle control rod ball joint to throttle lever and secure with nut and lock washer. Then hook throttle rod return spring in clip on ball joint.
(5)	Connect choke valve con- Screw driver. trol.
Place choke valve control tube on bracket and tighten clamping screw. Insert control wire in swivel on choke valve lever and tighten clamping screw.
279
TM 9-170G
52-54
ORDNANCE MAINTENANCE
(6)	Replace carburetor air ^-inch open end wrench. cleaner adapter.
Place air cleaner adapter on carburetor air intake and tighten adapter clamping screw.
53.	Carburetor controls (fig. 186).—a. Carburetor controls consist of hand throttle, hand choke, accelerator pedal, and linkage.
b.	The hand throttle control is of the wire and flexible housing type and is used when starting the engine .or when making engine adjustments. For proper use, see TM 9-705.
c.	The choke control is of the wire and flexible housing type and is used for starting the engine. For proper instructions on how to use, see TM 9-705.
d.	The accelerator operates the carburetor throttle by means of a bell crank and a cross shaft with two levers. The shaft assembly is mounted on the engine side of the dash. Rods with ball joint ends attached to levers and bell crank make the connection between the accelerator pedal and the carburetor throttle lever. Return springs are provided to return throttle to closed position when the accelerator pedal is released or throttle hand control button pushed in.
e.	Removal and replacement of hand throttle, hand choke, accelerator pedal, and linkage can be readily accomplished by referring to figure 186.
f.	It is important that levers and linkage work freely and do not bind.
54.	Fuel filter.—a. Description (fig. 187).—The fuel filter is located at the right side of the engine and is attached to the carburetor fuel inlet fitting by means of a close nipple.
(1)	Construction.—The fuel filter has a die cast head with two threaded bosses to take the fuel inlet and outlet fittings. Also threaded into the head casting is the metal fuel filter element and the glass fuel bowl. A spring metal clamping bail (clip) locks the bowl in position. The fuel filter element consists of a series of circular perforated disks assembled on a spindle.
(2)	Functioning.—Fuel delivered by the fuel pump is forced through the fuel line into the filter bowl, and on through the filtering element into the carburetor float bowl. The filtering element removes any particles of dirt from the fuel before it enters the carburetor bowl.
280
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HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS 54
(3)	Specifications.
Make________________________________________
Ordnance No_________________________________
Manufacturer’s No___________________________
White No____________________________________
Zenith.
A214340.
Z-F291X2.
361787.
b.	Trouble shooting.—See paragraph 526.
c.	Fuel filter removal.—Tools:
%-inch open end wrench.
%6-inch open end wrench.
(1)	Disconnect fuel line (fuel %-inch open end wrench. pump to filter.')
Disconnect fuel line fitting flare tube nut at filter inlet elbow.
Mir ..'	.	■ ■■ ■ .	jj
Jr ,	.	p.
'S*	< M
f । jk	Ml i
• ■	/ I
Vxl Mlbs •
•■	" 'S i
CARBURETOR, ASSEMBLY -
Z-O-9232	RA PO 8008
- - ' * ... ................... ■
Figure 187.—Fuel filter, installed.
281
TM 9-1706
54	ORDNANCE MAINTENANCE
(2)	Remove fuel filter assembly %6-inch open end wrench. from carburetor.
Disconnect filter nipple from carburetor inlet fitting and remove filter with nipple.
d.	Fuel filter disassembly (fig. 188) .—Tools:
%6-inch open end wrench.
(1)	Remove filter inlet and out- %6-inch open end wTrench. let fittings.
Disconnect outlet nipple and inlet elbow from filter head.
(2)	Remove filter bowl.	None.
Release filter bowl locking bail (clip) and unscrew bowl from head. Then remove bowl gasket.
(3)	Remove filter element. None. •
Remove fuel filter element from head by unscrewing it by hand.
e.	Maintenance.— (1) The fuel filter should be disassembled and cleaned when the carburetor is removed for inspection and when dirt or water is visible in the bowl. Wash bowl and element with solvent, dry-cleaning, allow to dry, and blow out filter element with compressed air.
(2)	When cleaning filter head, inlet nipple, and outlet elbow, check threads and replace if threads show signs of stripping.
(3)	Inspect bowl gasket and replace if damaged.
(4)	If bowl locking bail has been sprung out of shape, replace.
(5)	Service data.
Filter---------------------------------------Metal element.
Filter spacing------------------------------------ 0.002 inch.
Length of filter element____________________________% inch.
f.	Fuel, filter assembly.—Tools:
%6-inch open end wrench.
(1)	Install inlet and outlet fit- %6-inch open end wrench. tings.
Connect outlet nipple and inlet elbow to filter head.
(2)	Install filter element. None.
Screw filter element into head and tighten by hand.
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HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS 54
diWH	A—ELB0W	E—gasket
BW	B —NIPPLE	F —ELEMENT,	ASS'Y
A----IMR 1	C — H EAD	G — BOWL
D —ELBOW	H —BAIL
»—H
'r^"	^****^	flf
F oWKIIIk /	fl Ml wc ‘	V	■
ISV imKI'TO- w W -x	\ I / « I T • -4”	> W	»
'111 H W	I r	i	•£
wWli/l/l /	1/3	1
~~—-----------
E	F	G	H
RAPD.33310
Figure 188.—Carburetor fuel filter, exploded view.
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TM 9-1706
54-55	ORDNANCE MAINTENANCE
(3)	Install filter bowl.	None.
Replace gasket in head and screw in bow]. Place bail over bowl and snap over filter head.
g.	Fuel filter installation.—Tools :
%G-inch open end wrench. y>-inch open end wrench.
(1)	Install fuel filter assembly. %6~inch open end wrench.
Screw nipple with filter attached into carburetor inlet fitting. When tight, filter should be in vertical position.
(2)	Connect fuel line.	%-inch open end wrench.
Connect fuel line from fuel pump to fuel filter inlet fitting with flared tube nut.
55. Fuel pump.—a. Description (fig. 190).—The combined fuel and vacuum pump is located at the lower right-hand side of the engine and is bolted to the engine crankcase.
(1)	Construction (fig. 189).—The combined fuel and vacuum pump is of the diaphragm type, with two chambers independent of each other, except that both diaphragms are actuated by a single rocker arm. The lower chamber supplies fuel to the carburetor and the upper chamber acts as a vacuum booster for the windshield wiper at low manifold depression. The diaphragms, which are made of a specially treated material, are held between metal disks. These disks also hold the diaphragm link rods, which are attached to the rocker arm. Coil springs are used to actuate the diaphragm on the return stroke of the rocker arm. An air dome is used at the fuel pump outlet to eliminate surging of fuel delivered to the carburetor. The inlet and outlet valves are interchangeable, each consisting of a fiber disk valve and spring assembled in a cage. Two retaining clamps with screws hold the valve assemblies in position.
(2)	Functioning.—An eccentric on the camshaft actuates the fuel pump rocker arm which is linked to both diaphragms.
(«) Fuel element.—Fuel is drawn from the supply tank into the pump fuel chamber on the suction stroke of the pump. The return stroke of the pump forces fuel into the carburetor float bowl. When the carburetor float bowl is filled, its float valve is closed, thus creating a pressure in the fuel pump chamber. This pressure holds the fuel pump diaphragm in the upward position where it will remain inoperative until the carburetor bowl requires more fuel.
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HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS 55
Figure 189.—Fuel pump, sectioualized.
285
RA FSD I850A
TM 9-1706
55
ORDNANCE MAINTENANCE
(Z>) Vacuum element.—When the windshield wiper is operating with the inlet manifold vacuum less than the pump vacuum, the upward stroke of the diaphragm expels the air in the chamber through the outlet valve into the intake manifold. On the return stroke the diaphragm creates a suction in the chamber, drawing air through the inlet passage from the windshield wiper. When the manifold vacuum is greater than the vacuum created by the pump or when the windshield wiper is not in use, the manifold vacuum holds the diaphragm in the upward position where it wil] remain inoperative until the manifold vacuum drops.
Figure 190.-—Disconnecting fuel pump lines.
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HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS
(3)	Specifications.
Make_____________________________________
Type-------------------------------------
Ordnance No------------------------------
Manufacturer’s No________________________
White No_________________________________
Weight___________________________________
b. Trouble shooting.
Symptoms and probable cause
(1)	Fuel leaks.
{a) Loose fuel pump bowl.
(/>) Loose fuel line fittings.
(c)	Loose fuel pump cover.
(d)	Broken fuel pump diaphragm.
(2)	Low fuel pressure.
(a)	Air leaks in system.
(6)	Fuel pump diaphragm out of order.
(3)	Lack of fuel.
{a) Broken fuel pump diaphragm.
(5) Sticking fuel pump inlet and outlet valves.
(c) Loose fuel pump cover.
AC.
Mechanical.
C74115.
AC-1537105. 344947.
5 pounds.
Probable remedy
{a) Tighten bowl cap screw. Replace screw and bowl gaskets if necessary.
(6)	Tighten fuel pump inlet and outlet fittings. Replace if threads are stripped.
(c)	Tighten cover screws.
(d)	Replace diaphragm.
(a)	Tighten connections.
(b)	Replace diaphragms.
(a) Replace.
(&) Clean and free valve of all gummy deposits, or replace complete valve assembly.
(c) Tighten cover screws.
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c.	Fuel and vacuum pump removal.—Tools:
%-inch open-end wrench.
%-inch open-end wrench
(1)	Disconnect fuel pump lines. %-inch open end wrench.
Disconnect fuel pump line inverted flared tube nut from pump inlet fitting and carburetor fuel line inverted flared tube nut from pump outlet fitting (fig. 190).
(2)	Disconnect vacuum pump %-inch open end wrench. lines.
Disconnect windshield wiper vacuum line inverted flared tube nut at vacuum pump inlet fitting and vacuum line inverted flared tube nut at vacuum pump outlet fitting.
(3)	Remove pump from engine. %-inch open end wrench.
Remove two cap screws and lock washers that attach pump to its pad on engine crankcase (fig. 191). Then lift off pump, two gaskets, and the metal shim.
Hammer.
File.
Long nose pliers.
%6-inch open end wrench.
d.	Fuel pump disassembly (fig. 192).—Tools: Screw driver.
%-inch open end wrench.
Punch.
%6-inch open end wrench.
(1)	Remove vacuum chamber cover and filter screen.
Remove cap screw and gasket holding cover to body and lift off cover and gasket. Lift out screen retainer and remove screen.
(2)	Remove vacuum pump Screw driver. body assembly.
Remove 10 fillister head screws and lock washers securing vacuum body. Before lifting off the vacuum body assembly, scribe a line on the edge of the flanges so that they will be reassembled in the same position.
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Figure 191.—Fuel and vacuum pump removal.
476794°—42----19
289
PUMP, FUEL AND VACUUM, .	SCREW, CAP
ASSEMBLY—AC-1537105	WASHER, LOCK	WRENCH
.....	..... . -a.,. .-A.A..	. _	______________ ......./..........
TM 9-1706
55
ORDNANCE MAINTENANCE
o’ K'	r:
J — HH
-------y . -
-	irgrw
o—*\** .)	’
'•***' FF
lW'	/	Q....-EE
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G—---f Q-----NN	>
H ®Xe
J__1---1	cJMMBMMIW
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ukkK ' ■■■	■ fll---z
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N_—^__—.— —] b^bii^q ’W
o______-^?L9sw|	—-»
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_  . .	'. P Q R S T i U _ RA PO 3264 A
Figure 192.—Fuel pump, exploded view.
290
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ENGINE FOR SCOUT CARS
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55
(Screw—AC-1537108.
A [Gasket—AC-1523128.
B.	Bowl—AC-1537109.
C.	Gasket—AC-1523128.
D.	Screen assembly—AC-1537193.
E.	Cover—AC-1537107.
F.	Dome assembly—AC-1523319.
G.	Screw—AC-132900.
H.	Retainer—AC—1523664.
J.	Valve, with cage, assembly—AC-1523106.
K.	Diaphragm, with rod, assembly—AC-1523132.
L.	Retainer—AC-1523259.
M.	Spring—AC-1523124.
(Rod—AC-1523123.
[Washer—AC-1521248.
O.	Arm—AC-1537106.
P.	Bushing—AC-1523221.
Q.	Pin—AC-1523725.
R.	Washer—AC-1521788.
S.	Spacer—AC-1521909.
T.	Spring—AC-1521427.
U.	Body assembly—AC—1523831.
V.	Link (right hand)—AC-1522078.
W.	Link (fuel)—AC-1522077.
X.	Link (left hand)—AC-1522079.
Y. Retainer—AC-1523191.
Z. Washer—AC-1522002.
AA. Spring—AC—1523921.
BB. Retainer—AC—1523150.
CC. Diaphragm, with rod, assembly—AC-1523809.
DD. Spring—AC-1523804.
EE. Seat—AC-1523805.
FF. Body—AC-1523779.
GG. Screen—AC-1523802.
HH. Gasket—AC-1523801.
JJ. Plate—AC-1537195.
(Screw—AC-1523829.
[Gasket—AC-1523801.
LL. Retainer—AC—1523803.
.... (Screw—AC-855493.
{Washer, lock—BECX3E.
NN. Gasket—AC-1521953.
OO. Hair—AC-1521553.
(3)	Remove vacuum diaphragm None.
spring.
Lift out diaphragm spring and spring seat.
(4)	Remove vacuum inlet and Screw driver.
outlet valve assembly.
Remove retainer screw and lift off retainer, valves, and gaskets.
(5)	Remove vacuum diaphragm None.
assembly.
Press down on diaphragm, unhook it from rocker arm link, and lift out diaphragm assembly. Then take out oil seal spring, upper and lower oil seal retainer, and leather washer.
(6)	Remove fuel pump bowl. %-inch open end wrench.
Remove cap screw with gasket and lift out bowl, gasket, and screen.
(7)	Remove fuel pump cover Screw driver. assembly.
Remove 10 fillister head attaching screws and lift off cover assembly.
(8)	Remove fuel inlet and out- Screw driver.
let valves. -
Remove valve retainer screws and lift out retainer, inlet and outlet valves, and gaskets.
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(9)	Remove fuel pump dia- None. phragm.
Press down on diaphragm, unhook it from rocker arm link, and lift out diaphragm assembly and return spring.
(10)	Remove rocker arm assem- Punch.
bly.	Hammer.
File.
File off bur from rocker arm pin and remove washer. Then drive pin out of pump body to release rocker arm assembly and spring.
(11)	Remove vacuum and, fuel None. diaphragm links.
Press out by hand the link bushing, releasing right- and left-hand vacuum diaphragm link, fuel and diaphragm link, link spacer, and two spacer washers from rocker arm.
(12)	Remove air filter hair. Long nose pliers.
Pull out the hair retainer and filter hair from pump body.
e.	Maintenance.— (1) Fuel pump pressure and vacuum tests can be made before the pump is removed for disassembly and after it has been overhauled and reinstalled.
(a) Using a fuel pump analyzer, connect the adapter tee into the fuel pump outlet line and connect the analyzer hose to the tee (fig. 193). Check the pressure at various engine speeds to duplicate actual operating conditions. Normal pressure should be between 2% and 4 pounds.
(Z>) Connect adapter tee into fuel pump inlet line. Connect analyzer hose to tee and run engine (fig. 194). The pump vacuum should be from 8 to 10 inches.
(2) After the fuel and vacuum pump has been disassembled, it should be cleaned and parts inspected thoroughly as follows:
(a) All parts that show signs of wear to the extent of causing the pump to become inoperative should be replaced.
(&) Inspect diaphragms and replace if worn or punctured.
(’
1.	GEAR —HM-45266A	6	9. NUT—BBBXIB	17. RING-HM-4387A
2.	PIN - HM-4809A	1 0.	SCREW, CAP —BCBXIBF	1 8.	GEAR-HM-22154A
3.	WASHER-HM-2047A	1 1.	SHAFT-HM-22124A	19.	COVER-HM-45171B
4.	BODY—HM-41124C	12.	KEY-BGAX4D	20.	WASHER, LOCK-BECXIG
5.	PISTON — HM-22129A	13. RING-HM-4387A	rcay-ik
6.	SPRING—HM-1347A	„	W	14. GEAR-HM-22I54A 2' S
7.	FITTING —HM-ISB5A	13. KEY-BGAX4D	22. SCREW, CAP BCAXIAD
8.	NUT—HM-1660A	<	16. SHAFT—HM-22155A	23. STRAINER, ASSEMBLY-HM-45179-BS
9	W.
]0	®	RA PD 8049
Figure 201.—Oil pump, exploded view.
476794°—42---20
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Remove six cover-to-body cap screws and lock washers and remove cover from pump body.
(3)	Remove oil pressure adjust- %-inch open end wrench. ing screw assembly.
Remove oil pressure adjusting screw fitting nut from cylindrical boss. The adjusting screw and lock nut will come away with the fitting nut.
(4)	Remove oil bypass piston. Small screw driver.
Shake out from cylindrical boss the spring button, spring, and piston. If these parts are stuck by gummy oil deposit, insert small screw driver in bypass hole located in boss and push them out.
(5)	Remove drive gear.	Pin punch.
Hammer.
Arbor press.
Pliers.
Drive out retaining pin from gear boss. Place pump in press with steel blocks under gear and press out shaft. Then remove Woodruff key from shaft and slide off fiber thrust washer.
(6)	Remove pump gear from Arbor press.
drive shaft.	Pliers.
Screw driver.
Push shaft with pump gear from body and place in arbor press. First press gear back on shaft about % inch; this will allow7 removing snap ring from groove in shaft. Then press gear off shaft and remove Woodruff key.
(7)	Remove pump idler gear. Arbor press.
Screw driver.
Pull idler gear and shaft from body and repeat above step. No key is used on idler gear shaft.
e.	Maintenance and adjustments.— (1) The oil pressure can be adjusted w’ithout removing the oil pan, in the following manner:
(a) Remove three oil pan cap screws holding brake vacuum booster to crankcase and lower cylinder assembly.
(ft) Remove adjusting hole plug located on left side of engine oil pan.
(c) Using special oil adjusting T-socket wrench on the adjusting screw7 hex head nut and a crowfoot wrench on the adjusting screw
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locking nut, loosen locking nut and turn adjusting screw in to increase pressure, or out to decrease pressure (fig. 202).
(2) Dirt and carbon may cause relief valve piston to stick, resulting in low oil pressure. This condiiton can sometimes be corrected by tightening the adjusting screw to force the plunger loose. If this does not correct the condition, remove pump and inspect valve and valve spring.
(3) Before disassembly, check gears for backlash and shaft for end play. See section XIV for clearance. End play can be reduced by grinding the pump body face with an abrasive compound on a flat surface.
^11© ~ L. "’i	v
ITT: / ■ ' N ' i l
WRENCH• * /'<.	..
* ~ 11^.,
lb. ' x /I /
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WRENCH fifeggXfc... M/.M
cf'kZ ■ z	w
Figure 202.—Oil pump pressure adjustment.
(4)	After the oil pump has been disassembled clean all parts in solvent, dry-cleaning, and—
(«) Check gears for worn, cracked, or broken teeth and replace if necessary.
(&)	Inspect cover cap screws for damaged threads and replace if stripped.
(c) Inspect strainer and replace if crushed or damaged.
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(d) Inspect pressure relief valve spring for signs of permanent set or break and replace if necessary.
(5) Service data.— (a) Pump gears.
Type------------------------------
Number of teeth___________________
Pitch_____________________________
Gear backlash_____________________
Pressure angle____________________
Oil pressure______________________
Steel spur gear.
10.
10.
0.003 to 0.006 inch.
30°.
35 to 40 pounds at 1.000 rpm.
0.003 inch.
Shaft end play___________________
(6) Pressure relief spring.
Free length------------------------- 1%6 inches.
Pounds pressure at 1%6 inches-______4% pounds.
f.	Oil pump assembly.—Tools: Arbor press.
Hammer.
%6-inch open end wrench.
(1)	Install pump gear on shaft.
%-inch open end wrench.
Pipe wrench.
Arbor press.
Place shaft in press, insert Woodruff key, and press gear on shaft far enough to allow snap ring to be replaced. Reverse and press gear in position at end of shaft.
(2)	Install idler gear on shaft. Arbor press.
Repeat above operation. No Woodruff key is used on idler gear shaft.
(3)	Install drive gear on shaft. Arbor press.
Hammer.
Insert drive shaft with pump gear into pump body and place in press. Then replace fiber washer, insert Woodruff key, and press gear in position, lining up the pin hole in gear hub with hole in shaft. Remove from press, insert, and drive home retaining pin.
(4)	Install pump cover to body. %6-inch open end wrench.
First slide the idler gear and shaft into the body, meshing the idler gear with the pump gear Then place cover on body and replace six cap screws and lock washers.
(5)	Install bypass piston as- %-inch open end wrench. sernbly and adjusting screw.
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Insert piston, spring, and spring button into cylindrical boss in order named. Then insert adjusting screw fitting nut with adjusting screw and lock nut.
(6)	Install oil pump screen. Pipe wrench.
Screw screen connection pipe with screen into boss on cover
g.	Oil pump installation.—Tools:
%6-in open end wrench.
%6-inch socket wrench.
Speed handle.
%-inch open end wrench.
(1)	Install oil pump.	%6-inch open end wrench.
Position oil pump on main bearing web and replace three attaching cap screws and lock washers.
(2)	Install engine oil pan. %6-inch socket wrench.
Speed handle.
%-inch open end wrench.
Shellac new gasket on oil pan. Position pan on crankcase and replace 20 cap screws and lock washers attaching pan to crankcase and 5 cap screws and lock washers attaching pan to flywheel housing.
(3)	Replace oil in crankcase. %6-inch open end wrench.
Screw magnetic drain plug into crankcase and fill with required grade and quantity of oil.
Section XIII
PREPARING ENGINE FOR STORAGE
Paragraph
General--------------------------------------------------------------60
Cleaning ____________________________________________________________61
Draining of oil------------------------------------------------------
Preparing electrical equipment left in place-------------------------63
Spark plugs and distributor----------------------------------------  64
Fan belt tension-----------------------------------------------------65
Carburetor ________________________________________________________  66
Protection --------------------------------------------------------- 67
Inspection-----------------------------------------------------------68
Engine tag-----------------------------------------------------------69
60.	General.— a.	An engine which is not to be used for some time
will be stored, if practicable, in covered and closed storage.
b.	Before being stored, the engine should be overhauled and placed in thoroughly serviceable condition. If, for any reason, it is impos
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ORDNANCE MAINTENANCE
sible to overhaul the engine, a careful inspection must be made and the engine carefully tagged indicating repairs and new parts needed to make it serviceable. These tags must be securely attached to the engine and shellacked to protect them against oil and moisture.
c.	An engine which is to stand for several weeks must rest on its supports, or on pieces of timber bolted to the supports. The engine should never be allowed to rest on the floor with its weight supported by the base or oil pan.
61.	Cleaning.—The engine must be thoroughly cleaned before being placed in storage. This can be accomplished with solvent, drycleaning, brushes, and scraper over a drip pan and with the aid of compressed air or live steam if available.
62.	Draining of oil.—Drain the oil pan and slush with oil, lubricating, preservative medium. Drain slushing oil and refill oil pan to operating level with oil, engine, seasonal grade. Pour about % pint of oil, lubricating medium, into each cylinder and crank the engine over by hand long enough to distribute the oil and to assure that it lubricates the valve stems, pistons, and cylinder walls.
63.	Preparing electrical equipment left in place.—All parts of the generator and starting motor except coils and windings, if left in place on the engine, must be coated with oil, lubricating, preservative medium. These units then must be covered first with a piece of paper, such as tar paper, building paper, or heavy wrapping paper, treated with oil to make it waterproof—or with oilcloth—then, if available, burlap or canvas should be put on over the paper to protect against any mechanical injury.
64.	Spark plugs and distributor.—Remove the spark plugs, the spark plug cables, and distributor from the engine. Place these parts in a heavy waterproofed paper sack and tag the sack with the engine number, etc., from which the parts were taken. Attach the sack to the engine. Be sure to plug the spark plug holes and the distributor shaft opening in the engine with wooden plugs to prevent foreign matter and moisture from getting inside the engine.
65.	Fan belt tension.—Loosen the tension on the fan belts by loosening the hand adjusting screw.
66.	Carburetor.—The carburetor float chamber and moving parts must be slushed out with oil, lubricating, preservative medium. This can be accomplished by removing the float chamber and spraying it or by inserting rubber tubing in the gasoline line connection at the carburetor and forcing oil through.
67.	Protection.—All exposed metal surfaces of the engine not protected by a good coat of paint or enamel must be coated with oil,
TM 9-1706
HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS 67-70 lubricating, preservative medium. This can be sprayed on or applied with a brush.
68.	Inspection.—All engines in storage should be inspected every 2 or 3 months and reslushed if necessary.
69.	Engine tag.—Each engine designated for storage must carry a tag. The following important information should appear on the tag:	,
a.	Name of vehicle from which the engine was removed or for which it was built.
b.	United States number of vehicle from which removed.
c.	Name of manufacture of engine.
d.	Bore and stroke.
e.	Manufacture’s type or model symbol.
f.	Manufacturer’s serial number.
g.	Government purchase number if purchased as a separate unit and not removed from a complete vehicle.
h.	Date placed in storage.
i.	Conditions; as new stock, rebuilt, overhauled, needs overhaul, needs repairs of___parts, robbed of----parts.
j.	If O. K. (as new or rebuilt), initials of inspector and date.
k.	Dates of subsequent periodical inspections and initials of inspectors.
I.	Any other information likely to be desired.
Section XIV
CONSOLIDATED SERVICE DATA
Paragraph
Clutch______________________________________________________________TO
Cooling system—water pump-------------------------------------------71
Electrical—generator and regulator----------------------------------72
Electrical—ignition system----------------------------------------  73
Electrical—starter_________________________:-------------------------74
Engine (stripped)---------------------------------------------------75
Fuel system________________________________________________________ 76
Lubrication system—oil pump-----------------------------------------77
70. Clutch.
Level travel:
To release____________________ %	inch.
Recommended------------------- %	inch.
For wear---------------------- %	inch.
Clutch balance:
Cover plate assembly--------%	ounce-inch.
Driven member assembly— %	ounce-inch.
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ORDNANCE MAINTENANCE
Driven disk:
Material____________._______
Friction facings____________
O. D________________________
I. D________________________
Thick_______________________
Total area__________________
Release levers:
High carbon steel. Woven or molded. 12 inches.
7 inches. 0.137 inch.
150 square inches.
Ratio___________________ 5% to 1-
Pressure plate:
O. D____________________ 12% inches.
Spring	press------------ 1,620 pounds maximum.
71. Cooling system—water pump.
Clearance between inner
edge of impeller blades and housing_____________
Backlash (drive gear)_____
72. Electrical—generator and
Brush spring tension______
End play of armature______
b. Regulator.
Carbon resistors—four used.
Resistance:
R1 marked 80____________
R2 marked 15____________
R3 marked 30____________
R4 marked 1_____________
Circuit breaker:
Resistance of voltage winding_________________
Armature air gap________
Contact point gap_______
Points close____________
Points open_____________
Voltage regulator:
Resistance of winding___
Armature air gap________
Contact point gap_______
Pressure of contact points-
0.010 to 0.035 inch.
0.000 to 0.002 inch.
regulator.—a. Generator.
64 to 68 ounces.
0.010 inch maximum.
76 to 84 ohms.
13.5 to 16.5 ohms.
28 to 32 ohms.
0.9 to 1.1 ohms.
49.7 ohms.
0.060 to 0.065 inch.
0.015 minimum.
13.0 to 13.5 volts.
0.5 to 4.0 amperes discharge.
15.8 ohms.
0.040 to 0.042 inch (measured when points are just breaking).
0.010 inch minimum.
7 to 8 ounces.
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Operating voltages:
Allowable variation-_ Plus or minus 0.15 volts.
Temperature F_________ 50°, 70°, 80°, 90°, 100°, 110°,
120°.
Volts_________________ 1A51, 14.48, 14.45, 14.39, 14.36,
14.33, 14.30.
Current regulator:
Armature air gap____________ 0.047 to 0.049 inch (measured
when points are j ust breaking).
Contact point gap___________ 0.010 inch minimum.
Pressure of contact points--7 to 8 ounces.
Operating amperes----------- 54 to 56 amperes.
73. Electrical—ignition system.—a. Distributor.
End play__________________ 0.003 to 0.010 inch when drive
gear is pinned to shaft.
Side play in bearings_____ 0.005 inch maximum. With new
bearings, 0.0005 inch minimum to 0.001 inch maximum.
Breaker point gap---.---
Breaker arm spring tension-Condenser capacity------
Advance_________________
0.020 inch maximum.
17 to 20 ounces.
0.20 to 0.25 mfd.
10° automatic.
Retard___________________
6° manual.
b. Spark plugs.
Gap--------
0.025 inch.
74. Electrical—starter.
Brush spring tension------
Torque tests:
No load speed with
Bendix.
Locked torque:
350 amperes___________
540 amperes___________
750 amperes-----------
75. Engine (stripped).
42 to 53 ounces.
4,800 rm]) with 11 volts and 65 amperes.
4 volts—11.1 pound-feet.
6 volts—17.3 pound-feet.
8 volts—23.5 pound-feet.
Cylinder block:
Bore size______________________ 3.999 to 4.001 inches.
Bores selected to variation of- 0.00025 inch.
Maximum oversize permissible— 0.050 inch.
Bore out-of-round______________ 0.0005 inch.
Taper within___________________ 0.0005 inch.
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Crankshaft:
Number of bearings		7.
Bearing journal diameter: F ront		2.497 to 2.498 inches.
F ront—intermediate		2.497 to 2.498 inches.
Rear—intermediate		2.497 to 2.498 inches.
Rear		2.497 to 2.498 inches.
Connecting rod journal		1.987 to 1.988 inches.
Thrust taken		Rear—intermediate.
End thrust		0.002 to 0.004 inch.
Crank pin out-of-round		0.00025 inch.
Run-out at intermediate journal 		0.002 inch.
Crankshaft main bearing: Quantity		7.
Undersize bearing available		0.002 inch, 0.020 inch. 0.030
Main bearing clearance		inch. 0.040 inch. 0.0025 to 0.0035 inch.
Torque wrench pull: Front and interior	J	[ foot-pound	 70.
	inch-pound	 840.
Center and rear	J	[ foot-pound	59%.
	[ inch-pound	 714.
Shims (3 on each side)		0.003 inch.
Flywheel and housing: Flywheel run out		0.004 inch.
Concentricity of housing bore		0.010 inch.
Piston: Diameter of piston at ring lands (Refer to engine section.) Top land (A)		3.972 to 3.968 inches.
Second land (B)		3.978 to 3.974 inches.
Third land (C)		3.978 to 3.974 inches.
Fourth land (D)		3.950 to 3.960 inches.
Clearance between piston and cylinder : Block		0.003 to 0.0035 inch.
Fit piston with feeler shim: Shim thickness		0.003 inch.
Pounds pull on scale		8 to 12 pounds.
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Oversize pistons available-------- 0.005 inch, 0.010 inch, 0.020
inch, 0.030 inch.
Piston pin hole ream___________ 0.999 to 0.998 inch.
Ring groove width:
Compression________________ 0.1265 to 0.1255 inch.
Oil________________________ 0.189 to 0.188 inch.
Piston pin:
Diameter—grind_________________ 0.9997 to 0.9998 inch.
Diameter—hole in piston-------- 0.999 to 0.998 inch.
Clearance between pin and piston
hole—Hand push fit.
Oversize pins available________ 0.003 to 0.005 inch.
Compression ring:
Quantity-----------------------3.
Type______________'____________ Butt joint.
Width__________________________ 0.1235 to 0.125 inch.
Gap_______________________ -- 0.015 to 0.020 inch.
Ring and groove clearance______ 0.001 to 0.003 inch.
Oil ring:
Quantity------------------------- 1.
Type_____________________________ Butt joint-heavy duty type.
Width____________________________ 1.975 inches.
Gap______________________________ 0.015 to 0.020 inch.
Ring and groove clearance________ 0.002 to 0.003 inch.
Connecting rod :
Center to center length__________ 8.002 to 7.998 inches.
Lower bearing____________________ Replaceable type.
Lower bore_________________________ 2.1350 to 2.1345 inches.
End float__________________________ 0.005 to 0.0010 inch.
Connecting-rod bearing, lower:
Material-----------------------
Bearing clearance--------------
Size feeler shim for checking bear-
Copper, lead.
0.0015 to 0.0021 inch.
ing :
Clearance (paper shim)-------- 0.002 inch.
Undersize bearings available-- 0.020, 0.030 inch. 0.040 inch.
[ foot-pound—56.
Torque wrench pull------------[inch-pound-672.
Camshaft:
Number of bearings--------------- 4.
Bearing journal diameter:
Front_______________________ 2.053 to 2.054 inches.
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ORDNANCE MAINTENANCE
F ront-intermediate________
Rear-intermediate__________
Rear_______________________
Run-out at intermediate bearing____
Bearing out-of-round_______________
Thrust taken_______________________
Thrust plate thickness_____________
Camshaft bearing:
Quantity_______________________
Diameter—ream:
F ront_____________________
F ront-intermediate________
Rear-intermediate__________
Rear_______________________
Bearing clearance______________
Cylinder head:
Torque wrench pul]
Valve seat width—exhaust.
Valve seat width—intake-intake valve:
Lash, hot______________________
Seat angle_____________________
Diameter head__________________
Length, over-all_______________
Stem diameter__________________
Guide ream_____________________
Stem to guide clearance________
Intake opens___________________
Intake closes__________________
Intake period__________________
Port diameter__________________
Exhaust valve:
Lash, hot______________________
Seat angle_____________________
Diameter head__________________
Length, over-all_______________
Stem diameter__________________
Guide ream_____________________
Stem to guide clearance________
Exhaust opens__________________
Port diameter__________________
2.053 to 2.054 inches.
2.053 to 2.054 inches.
2.053 to 2.054 inches.
0.001 inch.
0.00025 inch.
F ront.
0.070 to 0.060 inch.
4.
2.0565 to 2.0555 inches.
2.0565 to 2.0555 inches.
2.0565 to 2.0555 inches.
2.0565 to 2.0555 inches.
0.0015 to 0.0025 inch.
foot-pound—52% inch-pound—630. %2 inch.
%2 inch.
0.006 inch.
45°.
1% inches.
5%4 inches.
0.372 to 0.373 inch.
0.374 to 0.375 inch.
0.0015 inch.
5° BTDC.
55° ABDC.
240°.
1% inches.
0.006 inch.
45°.
1% inches.
5%4 inches.
0.001 to 0.0015 inch.
0.3437 to 0.3427 inch.
0.001 to 0.0015 inch.
45° BBDC.
1% inches.
316
TM 9-1706
HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS 75
Exhaust closes-----------------
Exhaust period-----------------
Valve lifter:
Diameter-----------------------
Clearance, block to lifter---------
Valve spring:
Free length____________________
Pounds pressure at 1.920 inches—
Pounds pressure at 1.594 inches—
Timing gears:
Backlash_______________________
Idler gear bearing clearance---
Crankshaft gear:
Material_______________________
Teeth__________________________
Camshaft gear:
Material-----------------------
Teeth--------------------------
Oil pump:
Pressure at 1,000 rpm----------
Gear backlash------------------
Diameter:
Housing bore---------------
Drive shaft________________
Idler shaft----------------
Drive gear, bore-----------
Idler gear, bore-----------
Clearance between—
Drive shaft and housing----
Drive gear to shaft________
Idler gear to shaft--------
Gear to housing (radial) — Gear to housing lower edge__ Relief valve to housing----
Pounds pressure at l5/lfi inches— Free length--------------------
Pounds pressure at 1%6 inches—
Oil filter:
Make___________________________
Element number-----------------
15° ATDC.
240°.
0.6235 to 0.6240 inch.
0.0005 to 0.0025 inch.
213/16 inches.
41 to 45 pounds.
75 to 80 pounds.
0.000 to 0.002 inch.
0.00075 to 0.001 inch.
Steel.
25.
Steel.
50.
35 to 40 pounds.
0.008 to 0.010 inch.
0.5015 to 0.5005 inch.
0.499 to 0.500 inch.
0.5030 to 0.5035 inch.
0.498 to 0.499 inch.
0.5055 to 0.5045 inch.
0.0005 to 0.0025 inch.
0.002 inch.
0.001 to 0.0025 inch.
0.005 to 0.002 inch.
0.0015 to 0.004 inch.
0.003 to 0.006 inch.
1%6 inches.
4% pounds.
Purolator.
Cartridge, assembly, WI-C-21126.
317
TM 9-1706
76-78
ORDNANCE MAINTENANCE
76. Fuel system.—a. Carburetor.—Venturi and jet sizes for Zenith model Z-IN-167SJ carburetor.
Main venturi No. 341_________
Idling jet No. 131___________
Main discharge jet No. 751____
Well vent No. 201_____________
b. Fuel filter.
Filter________________________
Filter spacing________________
Length of filter element______
c. Fuel pump.
Pressure______________________
Vacuum________________________
Main jet No. 29.
Power and accelerating jet No.
24.
Power jet valve No. 201.
Needle valve seat No 45.
Metal element.
0.002 inch.
% inch.
2% to 4 pounds.
8 to 10 inches.
77. Lubrication system-—oil pump.
Pump gears:
Type______________________ Steel spur gear.
Number of teeth___________ 10.
Pitch_____________________ 10.
Gear backlash_____________ 0.003 to	0.006	inch.
Pressure angle____________ 30°.
Oil pressure______________ 35 to 40 pounds at	1000 rpm.
Shaft end play____________ 0.003 inch.
Pressure relief spring:
Free length_______________ 1%6 inches.
Pounds pressure at l*y16 414 pounds.
inches.
Section XV
SPECIAL TOOLS AND EQUIPMENT
Paragraph
Clutch___________________________________________________________________78
Oil pump_________________________________________________________________79
Engine____________________________ ______________________________________80
Voltage regulator_____________a.________________ ________________________81
Carburetor_______________________________________________________________82
78. Clutch.—One accurate clutch rebuilder with following accessories :
3 lands for positioning pressure plate.
6 special screw clamps, for clamping clutch assembly on rebuilder face plate.
1 three-arm spider, for compressing cover plate.
318
TM 9-1706
HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS 78-82
1 center post (spindle).
1 adapter for assembling pressure plates.
1 lever adjusting sleeve (calibrated), for setting lever adjusting arm optional.
1 lever adjusting arm (feeler type) or lever adjusting dial indicator.
1 weighted collar, for release lever position when installing adjusting nuts.
1 splined pilot bar, for clutch assembly installation.
79.	Oil pump.
1	special T-socket wrench, for oil pump pressure adjustment nut.
1	crowfoot wrench, for oil pump pressure adjustment lock nut.
80.	Engine.
1 %-inch thin wall socket wrench.
1 tension indicating wrench.
1 engine disassembly stand.
1 piston ring gap filing fixture.
1 pilot bar, for valve tappet guide removal.
1 pilot bar, for valve stem guide removal.
1 line reamer, for camshaft bearings.
1 valve rack.
81.	Voltage regulator.
1 Fahrenheit thermometer 0° to 212°.
1 contact point file.
1 0.040-inch pin gage.
1 0.042-inch pin gage.
1 0.047-inch pin gage.
1 0.049-inch pin gage.
1 0.060-inch flat gage.
1 0.065-inch flat gage.
82.	Carburetor.
Zenith tool No. Z-C-161-25, for removing power and accelerating jet (general).
Zenith tool No. Z-C-161-82, for removing main discharge jet (general).
Zenith tool No. Z-C-161-80, for removing well vent.
Zenith tool No. Z-C-161-81, forre moving power jet valve.
319
TM 9-1706
ORDNANCE MAINTENANCE
Appendix
LIST OF REFERENCES
1. Standard Nomenclature Lists.
a. Cleaning, preserving, and lubricating materials_ SNL K-l.
■ ft. Scout cars M3A1________________________________ SNL G-67.
c. Current Standard Nomenclature Lists are as tabulated here. An up-to-date list of SNL’s is maintained as the “Ordnance Publications for Supply Index” (OPSI).
2. Explanatory publications.
a. Cleaning, preserving, lubricating, and welding materials and similar items issued by the Ordnance
Department_______________________________________ TM 9—850.
ft. Maintenance.
Automotive lubrication__________________________ TM 10-540.
Detailed lubrication instructions for ordnance material________________________________________ OF SB 6-
series.
Echelon system of maintenance___________________ TM 10-525.
Fire prevention, safety precautions, and accidents- TM 10-360. Maintenance and repair (3d and 4th echelon)_____TM 10-520.
Motor transport inspections_____________________ TM 10-545.
Storage of motor vehicle equipment______________ AR 850-18.
c.	Miscellaneous.
Hand, measuring, and power tools________________ TM 10-590.
List of publications for training_______________ EM 21-6.
d.	Scout car materiel.
Scout cars, M3, M3A1, and 4.2 mortar motor
carriage, M2__________________________________ TM 9-705.
Ordnance maintenance, power train for scout car M3A1________________________________________ TM 9-1705.
Ordnance maintenance, Hercules DJXB Diesel
engine for scout cars_________________________ TM 9-1707.
Ordnance maintenance, body and chassis for scout cars_________________________________________ TM	9-1709.
Ordnance maintenance, Buda 6DT 317 engine for scout cars_________________________________________ TM	9-1708.
The motor vehicle__________________________________ TM	10-510.
Military motor	vehicles____________________________ AR	850-15.
320
TM 9-1706
HERCULES JXD GASOLINE ENGINE FOR SCOUT CARS
e.	Transportation.
Military motor transportation___________________ TM 10-505.
Motor transport technical service bulletins----- QMC.
The “Army Motors” monthly (QMC motor trans-
port school)---------------------------------- QMC.
476794°—42---21
321
TM 9-1706
INDEX
Paragraph Page
Accessories---------------------------------------------- __ 42,46	172,243
Assembly:
Clutch------------------------------------------------------ 15	22
Engine (stripped)---------------------------------------- 41,45	164,223
Generator__________________________________________________  24	76
Regulator_________________________________________________   25	96
Battery, tune-up______________________________________________    9	g
Carburetor:
Accessories_________________________________________________ 82	319
Fuel system---------------------------------x--------	51-53	256
Storage preparation______________J______________________ 55	319
Tune-up------------------------------------------------- 9	10
Clutch:
Assembly---------------------------------------------------- 15	22
Data____---------------------------------------------------- 70	311
Description______________________________________________    10	n
Disassembly_______________________________________________   13	13
Inspection___________________________________________________ 7	4
Installation_______________________________________________  16	28
Maintenance___________,,________________________________ 14	20
Removal of assembly________________________________________  12	16
Repair____.______________________________________________     4	2
Special accessories________________________________________  78	318
Trouble shooting________________________________________. n	14
Coil, ignition_________________________________________________  28	101
Cooling system:
Data-------------------------------------------------------  71	312
Fan and pump_____________________________________________ 17-21	29
Inspection_______________________________1______________ 7	4
Repair__________________________________________________ 4	2
Data, consolidated service__________________________________ 70-77	311
Disassembly:
Clutch----------------_--------------------------------- 13	is
Engine (stripped)_______________________________________ 43	177
Regulator----------------------------------------------- 25	87
Starting motor__________________________________________ 35	133
Distributor:
Ignition---------------------------------------------------- 29	106
Storage preparation_______________________________________   54	310
Tune-up_____________________________________________________  9	9
322
TM 9-1706
INDEX
Engine:	Paragraph
Inspection_____________________________________________ 7, 68
Repair___________________________________________________   4
Tag_______________________________________________________ 69
Trouble shooting------------------------------------------- 8
Tune-up____________________________________________________ 9
Engine (stripped):
Accessories____________________________________________42, 46
Adj ustments--------------------------------------------   47
Assembly_______________________________________________ 41, 45
Cleaning__________________________________________________ 61
Description______________________________________________  39
Disassembly_______________________________________________ 43
Installation______________________________________________ 48
Maintenance----------------------------------------------- 44
Preparation for storage_________.---------------------- 60-69
Service data______________________________________________ 75
Special accessories--------------------------------------- 80
Tests_____________________________________________________ 47
Trouble shooting__________________________________________ 40
Equipment, special _ --------------------------------------78-82
Fan:
Belt tension_____________________________________________  65
Cooling system_________________________________________17-21
Filter_____________________________________________________ 28, 54
Fuel system:
Carburetor_____________________________________________ 51—53
Description____________________________________________ 49
Fuel—
Filter_______________________________________________ 54
Pump._____________________________________________________ 55
Inspection_________________________________________________ 7
Repair_____________________________________________________ 4
Service data____________________________________________   76
Trouble shooting__________________________________________ 50
Tune-up____________________________________________________ 9
Generator, electrical:
Adjustments_______________________________________________ 24
Assembly__________________________________________________ 24
Construction______________________________________________ 24
Description---------------------------------------------   24
Inspection------------------------------------------------- 7
Installation_____________________________________________  24
Maintenance----------------------------------------------  24
Repair_____________________________________________________ 4
Service data_______________________________________:--- 72
Trouble shooting_______________________________________ 23, 24
Page
5, 311
3
311
5
10
172, 243
248
164, 223
310
150
177
249
211
309
313
319
248
160
318
310
29 101, 280
256-280
254
280
284
5
3
318
254
10
72
76
59
59
4
78
72
3
312
56, 61
323
TM 9-1706
INDEX
Ignition system:	Paragraph
Coil_______________________________________________________ 28
Description________________________________________________ 26
Distributor________________________________________________ 29
Filter____________________________________________________  28
Inspection__________________________________________________ 7
Repair______________________________________________________ 4
Shielding__________________________________________________ 30
Spark plugs________________________________________________ 31
Trouble shooting___________________________________________ 27
Tune-up_____________________________________________________ 9
Inspection:
Clutch______________________________________________________ 7
Cooling system______________________________________________ 7
Data_______________________________________________________ 73
Engine___________________________________________________ 7, 69
Form__________________________’__________________________	6
Fuel system______________________________________________ 7
Generator and regulator__________________________________ 7
Ignition system_________________________________.2_______ 7
Lubrication system_______________________________________ 7
Starting motor___________________________________________ 7
Technical, description___________________________________ 5
Installation:
Clutch___________________________________________________   16
Engine (stripped)_________________________________________  48
Generator___________________________________'____________ 24
Regulator__________________________________________________ 25
Starting motor_____________________________________________ 38
Page
101
100
106
101
4
3
121
126
101
9
4
4
313
5, 311
4
5
4
4
5
5
4
28
249
78
100
150
Lists, nomenclature________________________________________
Lubrication system:
Description___________________________________1 _   ___
Inspection_____________________________________________
Oil-
Filler____________________________________________
Pump______________________________________________
Repair_________________________________________________
Service data___________________________________________
Trouble shooting_______________________________________
Maintenance:
Clutch_________________________________________________
Engine (stripped)______________________________________
Generator______________________________________________
Regulator______________________________________________
Service________________________________________________
Starting motor_________________________________________
Nomenclature lists_________________________________________
App.	320
56	297
7	5
58	298
59	301
4	3
77	318
57	298
14	20
44	211
24	72
25	91
2-4	2
36	141
App.	320
324
TM 9-1706
INDEX
Oil •	Paragraph
Draining___________________________________________________  &2
Filter______________,----------------------------------—	58
Pump________________________________________________________ 59
Pump accessories-__----------------------------------------  79
Page
310
298
301
319
Power plant:
Trouble shooting---------------------------------------
Tune-up________________________________________________
Pump:
Accessories________:-----------------------------------
Cooling system_________________________________________
Fuel--------------- -----------------------------------
Oil____________________________________________________
8	5
9	8
79	319
17-21	29
55	284
59	301
Radiator___________________________________________________ 21	55
Reference lists____________________________________________ App. 320
Regulator, electrical:
Assembly___________________________________________________ 25	96
Description-----------------------------------------------  25	79
Disassembly________________________________________________ 25	87
Installation_______________________________________________ 25	100
Maintenance________________________________________________ 25	91
Quick checks_______________________________________________ 25	85
Removal_____________________________________»__________	25	86
Repair______________________________________________________ 4	3
Service data________________________________________________ 72	312
Trouble shooting____________________________________________ 25	86
Voltage_____________________________________________________ 81	319
Removal of assembly:
Clutch_____________________________________________________ 12	16
Regulator__________________________________________________ 25	86
Starting motor_____________________________________________ 34	138
Repair jobs:
Allocation__________________________________________________ 4	2
Fuel system_______________________________________________   4	3
Lubrication-system-----------------------------------------  4	3
Service data__________________________________________________ 70-77	311
Service maintenance, definition----------------------------------- 2	2
Shielding________________________________________________________ 30	121
Spark plugs:
Ignition____________________________________________________  31	126
Storage preparation------------------------------------------ 64	310
Tune-up---------_-----■---------------------------------- 9	9
Special tools and equipment----------------------------------- 78-82	318
Starter, electrical:
Repair________________________________________________________ 4	3
Service data_________________________________________________ 74	313
325
TM 9-1706
INDEX
starting motor:	Paragraph	Page
Description________________________________________________ 32	133
Disassembly of components___________(_________________	35	138
Inspection------------------------------------------------7,36	5,141
Installation_______________________________________________ 38	150
Maintenance________________________________________________ 36	141
Reassembly of components______________________________ 37	146
Removal of assembly________________________________________ 34	138
Trouble shooting___________________________________________ 33	137
Storage: preparing engine---------------------------------- 60- 69	309
Tag, engine----------------------------------------------------- 69	311
Technical inspection_______________________________________ 5—7	4
Tests, engine (stripped)________________________________________ 47	248
Tools, special_______________________________________________ 78-82	318
Trouble shooting:
Causes______________________________________________________ 8	5
Clutch_____________________________________________________ 11	14
Engine (stripped)------------------------------------------ 40	160
Fan and pump_____________________________________________   18	32
Fuel system------------------------------------------------ 50	254
Generator---------------------------_----------------- 23,24	56,61
Ignition--------------------------------------------------- 27	101
Lubrication system_________________________________________ 57	298
Regulator__________________________________________________ 25	86
Starting motor___________________________________________   33	137
Symptoms_______________________________________________ _ _	8	5
Tune-up:
Fuel system_________________________________________________ 9	10
Power plant_________________________________________________ 9	8
Vacuum tests, tune-up____________________________________________ 9	10
Valve clearance, tune-up_______________________________________   9	10
Voltage regulator__________________________________________ 81	319
Water pump:
Cooling system  ______________________________________ 20	43
Service data__________________________________________ 71	312
[A. G. 062.11 (6-1-42).]
By ORDER OF THE SECRETARY OF WAR :
G. C. MARSHALL, Official:	Chief of Staff.
J. A. ULIO,
Major General, The Adjutant General.
Distribution :
R9 (2) ; IBn 9 (1) ; IC 9 (3).
(For explanation of symbols see FM 21-6.)
o
For sale by the Superintendent of Documents, Washington, D. C.
Price 45 cents
U. S. GOVERNMENT PRINTING OFFICE: 1942
326
NTSU LIBRARY
UNT LIBRARIES DENTON TX 76203
1001895689