BRAKE SYSTEM. - TM-10-3930-622-140029

consisting of a torque converter and hydraulic

wheel cylinder assembly, two brake shoe assemblies

transmission. The torque converter is bolted directly to

and a backing plate. The individual wheel cylinder

the engine flywheel and is completely enclosed by the

assembly, attached to the backing plate assembly, is

transmission assembly. The transmission assembly is

fitted between the upper ends of the two brake shoe

cooled by hoses from the radiator. The truck has a travel

assemblies and provides equal pressure on the

control hand lever mounted on the steering column and

individual brake shoes for a smooth braking action.

connected by linkage to the transmission assembly. This

Each brake shoe is attached to the backing plate

lever controls the direction of motion, forward and

assembly by means of an anchor pin which provides the

reverse. Power is transmitted from the transmission

fixed pivot point for the brake shoe assembly. Each

assembly to the power axle assembly by a short

brake shoe assembly is equipped with an adjustable

propeller shaft.

eccentric cam for adjusting the brake shoe to

compensate for lining wear.

b. The transmission uses self-adjusting, cork-faced

clutch disks for smooth forward-reverse shifting and for

e. Parking brake. The parking brake system is

high torque level output. Ball and roller bearings are

connected through linkage to a brake drum and shoe

used throughout and all gearing is precision straight spur

assembly mounted in the power axle assembly.

design. The control valve is integral in this compact,

Mechanical force is used to press the brake shoes

self-contained unit, as is the input pump.

against the brake drum and prevent the truck from rolling

from the parked position. The manual force is supplied

c. The clutches are contained in one large,

as the hand brake lever is pulled up.

balanced drum assembly, and the plates drive concentric

shafts. The outer shaft has a gear mounted on it which

1-15.

POWER AXLE ASSEMBLY.

is in direct mesh with the output gear on the output shaft.

This transmits forward rotation to the output shaft. The

a. The power axle consists of a differential with its

inner shaft has a gear mounted on it which is in mesh

housing, two axle shafts which transfer power from the

with the output gear through an idler gear.

This

differential to the final drives at the wheels, and the final

transmits reverse rotation to the output shaft.

drive system which transfers power from the axle shafts

to the wheels which are mounted on tapered roller

d. The main case is of two piece cast construction

bearings. Each shaft has an individual housing which

and the rear half contains a heavy diaphragm midwall

bolts to the differential housing, and holds the differential

which forms one side of a rigid straddle mounted support

positioned in its housing.

for the output gear and shaft. Oil passages run within

the walls of the case and there are no external lines

1-16.

UPRIGHT ASSEMBLY.

except for the cooler and safety seat valve.

a. General. The upright assembly consists of four

1-14.

BRAKE SYSTEM.

main assemblies as follows:

a. Service brakes. The truck uses hydraulically

b. Outer upright assembly.

The outer upright

operated, self-adjusting wheel brakes for slowing and

assembly is a welded one-piece assembly that is

stopping movement of the truck. As power is applied to

mounted to the power axle assembly and tilt cylinders

the brake pedal, the movement is transferred through

and encloses the hoist cylinder and inner upright

linkage to the master brake cylinder. In the master brake

assembly.

cylinder, the brake pedal movement is applied through a

c. Inner upright assembly.

The inner upright

piston to a reservoir of brake fluid. This forces brake

assembly is a welded one-piece assembly that is

fluid from the master cylinder into a tube at high

mounted within the outer upright assembly. The hoist

pressure.

cylinder, mounted in the base of the outer upright

b. The brake fluid, under pressure, is ported

assembly, is secured through the top of the inner upright

through a tube to wheel cylinders in the wheel brake

assembly. The inner upright assembly is raised or

assemblies. As the pressure is applied, pistons in the

lowered by action of the hoist cylinder. It serves as a

wheel cylinders are forced outward and apply pressure

guide for the lift carriage and supports a latch assembly

against brake shoes inside the wheel brake drums.

which insures the proper lowering sequence.

c. The wheel brake drums rotate with the wheels,

d. Crosshead assembly. The crosshead assembly

but the brake shoes are rigidly mounted on the backing

is mounted over the hoist cylinder. Chains attached to

plate on the axles. As the shoes are pressed against the

the lift carriage assembly, roll over the crosshead

inside of the brake drums, the brake drums are slowed

assembly and are secured to the hoist cylinder. As the

and stopped.

cylinder raises, the crosshead assembly raises,

tightening the chains and raising the lift carriage

d. The service brake assembly, mounted at each

assembly.

wheel end of the power axle assembly, consists of a