4-15. The clutches in the transmission are contained in
STEERING BOOSTER AND VALVE.
one large balanced drum assembly and the plates drive
concentric shafts. The outer shaft has a gear mounted
4-23. The rod end of the steering cylinder piston is
on it which is in direct mesh with the output gear on the
anchored to the vehicle. The cylinder and valve body are
output shaft. This transmits reverse rotation to the
connected to the wheels through linkage and the valve is
output shaft. The inner shaft has a gear mounted on it
linked to the steering gear by a control rod. Road shock
which is in mesh with the output gear through an idler
forces on the wheels tend to move the cylinder, but this
gear. This transmits forward rotation to the output shaft.
action also moves the valve body in relation to the spool,
Therefore, the drive train consists of only four gears.
which is being held by the control rod. Movement of the
The output flange slips within a sealed grease cavity.
valve body relative to the valve spool directs oil to the
This arrangement leads toward long seal life and
cylinder to compensate for the road shock loads and to
minimum leakage. The main case is of two piece cast
maintain vehicle directional control at the steering wheel.
construction and the rear half contains a heavy
diaphragm midwall which forms one side of a rigid
4-24. When the valve spool is moved in either
straddle mounted support for the output gear and shaft.
direction by movement of the steering wheel and control
Oil passages run within the walls of the case.
rod, oil is directed to the cylinder. This causes the
cylinder and valve body to move in the desired direction
POWER AXLE ASSEMBLY.
relative to the piston and rod which is anchored to the
vehicle. Movement of the cylinder and valve body,
4-17. The power axle assembly contains the gears,
which, through linkage, are connected to the wheels,
shafts, bearings and other components necessary to
steers the vehicle.
transmit power directly to the front wheels of the fork lift
truck. The power axle also supports the front weight of
4-25. Movement of the steering wheel in either
the vehicle and mounts service brakes which enable a
direction is transmitted through mechanical linkage to the
uniform braking force to be applied directly to the wheels.
control valve ball stud. Movement of the ball stud
The power axle assembly is mounted directly to the
causes movement of the control spool. Oil flow is
transmission assembly and frame assembly.
directed by spool position to either the head end or rod
end of the cylinder which causes the cylinder to extend
4-18. Driving power is applied to the bevel Sear and
or retract. Movement of the cylinder will continue as long
differential assembly in the power axle through the
as the control spool is offset by continued turning of the
propeller shaft connected to the transmission assembly.
steering wheel. When the steering wheel stops turning,
The differential assembly consists of a ring gear, pinion
the control spool stops and the cylinder and valve body
gears and side gears. The inner end of the drive shafts
move to center (neutral) position and stop. This is true in
are splined to connect directly to the differential side
any position of the steering wheel as steering pitman arm
gears. The truck wheels are rigidly attached to axle hub
stops are provided to prevent the cylinder from bottoming
and drum assemblies mounted at the outer end of the
with the wheels against the wheel stops. in the event of
power source failure, the ball check in the steering
control valve body will permit free flow of oil throughout
SERVICE BRAKE SYSTEM.
the steering unit. This permits the steering system to be
4-20. The service brake system consists of the brake
pedals and linkage, master cylinder assembly, hydraulic
lines to front wheels, wheel cylinder assemblies, brake
a. Ignition Switch and Starter Button. The ignition
drums and brake shoes.
switch is located on the lower right side of the instrument
cluster case. Push the switch upward to the ON position
4-21. Brake pedal pressure forces hydraulic fluid from
to activate the electrical system. (The direction shift
the master cylinder assembly through the brake line, into
lever must be in the N (neutral) position.) Depress the
the wheel cylinder assemblies.
The pressure of
starter button located on the lower left side of the
hydraulic fluid within each wheel cylinder body displaces
instrument cluster case to activate the starter solenoid
pistons which are coupled to the upper ends of the
which in turn will cause the starter motor to crank the
hinged brake shoes. The brake shoes are forced
engine. Release starter button when engine commences
outward, and the lining of each brake shoe applies
to operate. Push the ignition switch to the OFF position
friction force to the brake drum. When the brake pedal is
to shut off the supply of electric current to the ignition
released, the hydraulic fluid pressure from the master
system and to the electrically operated gages.
cylinder assembly is released and the pistons and brake
b. Choke Control. The choke control is located on
shoes return to their original positions by spring
the lower right side of the operator's seat on the cowl.
pressure. The surplus hydraulic fluid in the system then
The normal operating position for the choke control is
returns to the master cylinder.
pushed in as far as it will go. Pull out the choke control to