Section XXV STEERING SYSTEM
Two power steering systems are used for the M915 thru M920 vehicles: one for the M915 and one
for the M916 thru M920. The systems are identical, except for the following:
Auxiliary power cylinder and associated hydraulic lines - used on the M916 thru M920
2-76. STEERING SYSTEM.
AUXILIARY ASSIST CYLINDER. Piston moved back and forth by pressure from lines.
Connects to right wheel steering arm through auxiliary drag link. (M916 thru M920 ONLY.)
POWER STEERING GEAR. Hydraulically multiplies input torque from steering column and
transmits it to Pitman arm.
UNIVERSAL. Changes angle of torque from steering wheel and applies it to input shaft of
power steering gear.
STEERING WHEEL. Provides rotational torque to steering shaft, actuating steering system.
UNIVERSAL. Changes angle of steering torque.
HYDRAULIC PUMP AND RESERVOIR. Pump supplies hydraulic pressure to power steering
system. Reservoir provides a supply of oil to assure complete filling of hydraulic system.
STEERING GEAR RETURN LINE. Carries hydraulic fluid from steering gear back to
STEERING GEAR SUPPLY LINE. Carries hydraulic fluid under pressure from pump to
STEERING ARM. Transmits fore and aft movement from drag link to knuckle assembly.
DRAG LINK. Transfers motion of Pitman arm to steering arm and tie rod.
TIE ROD ASSEMBLY. Connects steering arms so that wheels turn together.
PITMAN ARM. Transfers steering torque (boosted by power steering gear to drag link).
AUXILIARY CYLINDER HYDRAULIC LINES. Carry fluid under pressure from the
steering gear to operate auxiliary cylinder.
POWER STEERING COOLER. Cools power steering fluid by means of finned unit on
vehicle grille, exposed to outside air. After the fluid is cooled, it is returned to the power