4-Ton, 6x6 Trucks (Diamond T Models 968a Cargo, 969a Wrecker, 970a Ponton, and 972 Dump)

[4-Ton, 6x6 Trucks (Diamond T Models 968a Cargo, 969a Wrecker, 970a Ponton, and 972 Dump)]
[From the U.S. Government Publishing Office, www.gpo.gov]

TM 9-811
111
4-TON, 6x6 TRUCKS (DIAMOND T MODELS 968A CARGO,
969A WRECKER, 970A PONTON, AND 972 DUMP)
(5) Remove Shaft Assembly from Vehicle. Slide the shaft assembly toward the front, pulling the rear end through the hole in the front motor support cross member, and remove it from the vehicle.
d. Propeller Shaft between Transfer Power Take-off and Hoist Pump.
(1) Disconnect Companion Flange at Slip Joint End of Shaft. Remove the cap screws, nuts and lock washers holding the flange yoke at the slip joint end of the shaft to the companion flange on the transfer power take-off drive shaft, then separate the flanges. The shaft assembly will be supported in the hole through the frame cross member.
Figure 105—Connecting Companion Flanges
(2) Disconnect End Yoke from Hoist Pump. Loosen the set screw holding the end yoke to the hoist pump drive shaft. Then drive end yoke off the end of the hoist pump shaft and remove the key (fig. 104).
(3) Remove Shaft Assembly from Vehicle. Work the shaft assembly forward through the hole in the frame cross member and then remove the assembly from the vehicle.
236
“ f
RA-PD 303795
TM 9-811
112
PROPELLER SHAFTS AND UNIVERSAL JOINTS
112. INSTALLATION.
a. Companion Flange Mounted Shafts.
(1) Install Shaft Assembly into Position. Raise the shaft assembly into position in the chassis, mating the companion flanges on the driving and driven units with the flange yokes on the end of the propeller shaft assembly, and insert two cap screws through the holes in the flanges to hold the assembly in place. Be sure that the slip joint is facing the source of the power.
Figure 106—Installing Needle Bearing
(2) Connect Companion Flanges. Install the cap screws, nuts and lock washers which were removed through the holes in the companion flanges and tighten securely (fig. 105).
b. End Yoke Shaft between Rear Axles.
(1) Connect End Yoke of Propeller Shaft Assembly to the Journal. Slip the end yoke end of the propeller shaft assembly into position, and tilt the universal joint journal at the front of the through shaft for the rear rear axle in such a way that it may be worked into position in the end yoke of the propeller shaft. Then install one needle bearing cage assembly through the hole on each side of the end yoke and over the trunnion journals (fig. 106). It will be necessary to tap the end of the needle bearing cage lightly in order to drive it into
237
RA-PD 303590 I
TM 9-811
112
4-TON, 6x6 TRUCKS (DIAMOND T MODELS 968A CARGO,
969A WRECKER, 970A PONTON, AND 972 DUMP)
place. When the needle bearing assemblies are in place, line up the slot in the outer face of each with the slot on the bearing cover plate, and install the bearing cover plate, lock plate and cap screws which were removed. (Do not use a lock plate on which both ears have been bent.) Tighten the cap screws securely and fold the unused ear of the locking plate up against the side of the cap screw to hold it in place.
(2) Connect Slip Joint Yoke to the Universal Joint Journal. Connect the slip joint yoke to the universal joint journal in the same manner in which the end yoke was installed (fig. 106).
Figure 107—Installing Slip Joint on Winch Propeller Shaft
c. Propeller Shaft between Transmission Power Take-off and Front Mounted Winch.
(1) Install Shaft Assembly into Place in Vehicle. Working from the front, install the propeller shaft assembly into place in the vehicle, sliding the end yoke end of the shaft through the hole in the front motor support cross member, and back against the power takeoff drive shaft. When installing the slip joint on the splined end of the propeller shaft, be sure to line up the shaft yokes as described in paragraph 112 (fig. 107).
(2 ) Install Universal Yoke to Power Take-off Drive Shaft. Line up the key way in the universal joint yoke with the key way in the power take-off drive shaft, then drive the yoke into place over the shaft and install the key. Tighten the set screw in the hub of the universal joint flange, using a Vs-inch socket head set screw wrench.
238

TM 9-811
128-129
BRAKES
assembly into the engine compartment lowering it into place on the mounting bracket, at the same time working the fan belts over the pulley. Be careful not to damage the gasket while lining the assembly up. Attach the air compressor in place with the cap screws and lock washers which were removed.
(2) Connect Air Compressor Water Lines. Connect the copper inlet water line to the air compressor inlet fitting on the air compressor head. Install the water pump outlet rubber hose over the end of the outlet tube on the air compressor head and tighten the hose clamp.
(3) Connect Compressor Discharge Line. Connect the air compressor discharge line to the fitting on top of the cylinder head.
(4) Add Water to Cooling System (par. 84).
129. GOVERNOR.
a. Description. Since the air compressor is running all the time the engine is in operation, a governing device is required to limit the amount of air delivered to the reservoirs. A governor assembly is mounted on the front of the cowl in the engine compartment which limits this pressure to 105 pounds per square inch. The governor consists of a Bourdon tube exerting pressure on a valve. The Bourdon tube is C-shaped and closed at one end with the other end connected with the reservoirs. When the pressure in the reservoir reaches 105 pounds per square inch, the tube is straightened out a sufficient amount by this pressure to operate the valve in the governor which opens an unloader line which discharges all air pumped by the compressor to the atmosphere. When the pressure drops, the tube tends to curl up again, closing the valve which causes air to be delivered to the reservoirs once again.
b. Maintenance. A curled hair air strainer is provided at the base of the governor assembly. Disconnect the air line between the governor and the air supply valve at the governor and then remove the hexagon plug at the bottom of the air strainer elbow and remove the strainer assembly. Wash the strainer assembly in a suitable dry-cleaning solvent, and then dip in engine oil and allow to drain before replacing on the governor. Slide the strainer assembly into the housing at the base of the governor and replace the hexagon plug. Connect the air line between the governor and the air supply valve to the governor.
c. Removal.
(1) Release Air Pressure. Open the drain valve on the reservoir, and release the air pressure from the air brake system.
(2) Disconnect Air Lines. Disconnect the air lines running between the governor and the air compressor, and between the governor and the air supply valve, at the governor.
(3) Remove Governor. Remove the nuts and lock washers holding the governor assembly to the dash, and remove the governor and spacers from the mounting screws (fig. 126).
267
TM 9-811
129-130
4-TON, 6x6 TRUCKS (DIAMOND T MODELS 968A CARGO,
969A WRECKER, 970A PONTON, AND 972 DUMP)
d. Installation.
(1) Install Governor. Install the spacers over the governor mounting screws, install the governor into place, and replace the nuts and lock washers which were removed.
(2) Connect Air Lines. Connect the air lines running between the governor and the air compressor, and between the governor and the air supply valve, to the governor.
Figure 127—Removing Brake Valve Mounting Screws
130. BRAKE VALVE.
a. Description. The brake valve applies and releases the brakes. The amount of air pressure delivered to the brake chambers is in exact proportion to the amount of pedal travel, since the brake valve is designed to balance the pressure controlling the valve in relation to pedal travel and thus controlling the amount of air delivered to the brake chambers. The brake valve is mounted on a bracket attached to the frame rail underneath the floorboards on the driver’s side of the cab.
b. Removal.
(1) Remove Left Floorboard. Remove screws holding the floorboard in place, and remove the board from the left side of the cab.
268

TM 9-811
169
4-TON, 6x6 TRUCKS (DIAMOND T MODELS 968A CARGO,
969A WRECKER, 970A PONTON, AND 972 DUMP)
cable guide, over the outer mast sheave, and then down through the opening in the top Of the wrecker frame (fig. 186). Then pull the end of the cable down and engage it in the U-bolt eye of the winch drum
Figure 187—Winding Cable Onto Winch Drum
cable clamp. The winch drum should be turned so that the U-bolt clamp is facing toward the rear of the vehicle, then the cable is pulled straight down and installed through the U-bolt eye. Adjust the cable so that it extends about an inch through the U-bolt, and tighteh the U-bolt nuts securely.
340
1SS3ESp
TM 9-811
169
WRECKER
(2 ) Wind Cable onto Drum. Stretch the cable out in back of the truck and hook it on to a light load. Then, using the hand operating crank, wind the cable onto the drum while guiding it with a pair of hands, as shown in figure 187. The man guiding the cable should wear gloves to avoid cutting his hands on sharp strands on the cable. As the layers of the cable approach the edges of the drum, cranking should be done very slowly so that a pry bar may be used to force the layers
Figure J 88—Using Pry Bar to Force Layers of Cable Close Together
of cable close together to get a good tight wind (fig. 188). When the , cable has been wound far enough onto the drum, engage the pinion gear with the drum gear to hold it in position.
(3) Grasp the eye of the drag brake arm with one hand and pull it out until the opening at the inner end of the eye is spread far enough so that the cable may be slid through it, then release the arm with the cable running through the brake arm eye. Hook the end of the cable on the body bolster ring and wind the cable tight to secure the boom in a rigid position.
341

DUMP PUMP AND HOIST
TM 9-811
178
hoist assembly so that it does not fall down. Then shift the valve control lever on the pump to the release position to allow the piston rod to move down into the cylinder. When the piston rod is clear of the body cross head, pull it forward and lower it in a horizontal position so that it rests on 2 x 4 across the frame in front of the hoist trunnion.
Figure 196—Dump Body Blocked, Hoist Removed
( 6 ) Remove Hoist Assembly. Remove cap screws, lock washers and flat washers from the ends of the trunnion journals through the holes in the frame rails and then remove the spacers. Then remove the hoist trunnion tie bolts, nuts and lock washers from the hoist trunnion brackets (fig. 194). Push down on the piston rod to raise the trunnion journals from the sockets in the frame. Support the rear end of the hoist cylinder on another 2x4 across the frame (fig. 195). Remove the bolt, nut and lock washer from one of the lift arm collars and then
351
jRA-PD 3040^1
TM 9-811
178
4-TON, 6x6 TRUCKS (DIAMOND T MODELS 968A CARGO,
969A WRECKER, 970A PONTON, AND 972 DUMP)
remove collar. Remove tension link which was disconnected, when lift arm collar was removed. Then remove hoist assembly from chassis.
b. Installation.
(1) Place Hoist Assembly in Chassis. Lift the hoist assembly into position on top of the frame and lay it flat with the trunnion pointing towards the rear of the truck. Install the ends of the connecting links over the trunnion journals and install the lift arm collar (fig. 197). Then work it into position so that the trunnion journals drop into their
Figure 197—Installing Lift Arm Collar
seats in the sockets in the frame rails and the cylinder is resting on the frame cross member. Install the clamp bolts, nuts and lock washers in the hoist trunnion brackets to hold the journals in place. Install the spacers against the trunnion journals through the openings in the frame rails, and install cap screws, plain washers and lock washers.
(2) Connect Piston Rod to Cross Head. Lift the hoist assembly into a vertical position and release the valve control lever on the pump so that the piston rod may be pulled out (fig. 198). Tip the assembly back and line up the piston rod in the cross head and install the bolt, nut and lock washer, then turn valve control lever on the pump to the hold position.
(3) Connect Control Cable. Connect the yoke from the end
352
RA-PD 304795
DUMP PUMP AND HOIST
TM 9-811
178-179
of the control cable to the valve lever on the pump, using a cotter and clevis pin, then attach the cable assembly to the bracket on the pump with the U-bolt, nuts and lock washers (fig. 199).
(4) Connect Propeller Shaft. Connect the propeller shaft between the transfer power take-off and the dump pump, as described in paragraph 112.
Figure 198—Tipping Hoist Cylinder Back
(5) Lower Body. Raise the body just high enough to permit the removal of the 4x4 braces, and lower it until it rests on frame rails.
(6) Connect Body Stop Spring. Wire the body stop spring to the rear frame cross member.
179. PUMP ASSEMBLY.
a. Removal.
(1) Raise the body, and block it in a raised position. Remove the hoist cylinder drain plug and drain the oil.
( 2 ) Disconnect the pump valve control cable, as described in paragraph 178.
734619 0 - 47 - 23
353
lessor
TM 9-811
179
4-TON, 6x6 TRUCKS (DIAMOND T MODELS 968A CARGO,
969A WRECKER, 970A PONTON, AND 972 DUMP)
(3) Disconnect the propeller shaft between the pump and the transfer power take-off, as described in paragraph 111.
(4) Disconnect the high-pressure pipe running between the pump and the cylinder at the pump.
(5) Remove Pump. Remove the cap screws and lock washers holding the pump to the cylinder manifold assembly and remove the pump and pump gasket.
Figure 199—Installing Control Cable Clamp U-Bolt
b. Installation.
(1) Install the pump and gasket in position on the cylinder manifold assembly and replace with cap screws and lock washers which were removed. Use a new gasket.
(2) Connect the high-pressure pipe running between the pump and the cylinder to the pump.
(3) Connect the propeller shaft between the power take-off on the transfer and the pump, as described in paragraph 112.
(4) Connect the pump valve control cable to the valve lever on the pump, as described in paragraph 178.
(5) Add oil to cylinder (par. 24).
(6) Remove braces and lower the body.
354