TRANSMISSION AND DRIVE SHAFTS

TM 10-3930-638-24&P

alarm switch, and START swith; LAMP TEST position

b. Instrument Panel Switches and Gage Lights (cont).

applies power to illuminate HYDRAULIC FILTER,

5. IGNITION SWITCH. Four position key switch;

transmission temperature, and engine temperature

unmarked position (key turned to left) applies power to

indicators.

VEHICLE LIGHTS switch enabling lights to be turned on;

6. START SWITCH. Applies power to energize starter

OFF position disconnects power from ignition and light

relay by means of lockout relay and neutral start switch.

system; ON position applies power to VEHICLE LIGHTS

With starter relay energized, starter solenoid energizes, in

switch. gages. indicators (oil pressure and alternator lamps

turn, cranking starter motor to start engine.

will illuminate), fuel pump. fuel injection pump, back-up

1-20. TRANSMISSION AND DRIVE

SHAFTS

controlled by declutch valve, which is mechanically linked

to operator's declutch pedal.

1. FRONT DRIVE SHAFT. Connected between

6. CHARGING PUMP AND FILTER. Draws oil from

center drive shaft and front axle; connected to front axle

transmission sump through oil suction screen and directs

yoke by universal joint and to center drive shaft by a

the oil through pressure regulating valve and filter. Filter

yoke with internal splines. Rear of front drive shaft is

removes impurities from oil.

supported by a bearing.

7. CONTROL VALVE ASSEMBLY. Directs oil under

2. CENTER DRIVE SHAFT. Connected between

pressure to the desired directional and speed clutch.

transmission output shaft and front drive shaft. Connection

Directional and speed control valves connected by push-

accomplished by universal joints.

pull type cables to operator's transmission direction and

3. REAR DRIVE SHAFT. Connected between trans-

speed selector levers.

mission output shaft and rear axle by universal joints.

8. AXLE DISCONNECT. Controls engagement and

4. TORQUE CONVERTER. Integral part of trans-

disengagement of transmission drive to front and rear

mission; multiplies engine power.

axles. Pulling lever outward disconnects drive to front and

5. TRANSMISSION. Consists of torque converter,

rear axles; pushing lever inward engages drive. This is used

transmission, charging pump and filter, control valve

only when the truck is to be towed to a new location.

assembly, modulation valve, and parking brake. Includes

9. TRANSMISSION OIL COOLER. Mounted at rear

declutch feature which neutralizes transmission. This

of truck, in front of radiator; cools transmission hydraulic

accomplished by declutch valve spool in control valve

oil.

assembly. Flow of hydraulic oil to declutch valve spool is

1-11