TM 9-2320-272-24-3
Section XI. POWER STEERING SYSTEM MAINTENANCE
4-114. POWER STEERING SYSTEM MAINTENANCE INDEX
General Information
Upper and Lower Steering Column Maintenance
Steering Gear (ROW) and Mounting Bracket Replacement
Steering Gear (Sheppard) and Mounting Bracket Replacement
Steering Gear (Ross) Repair
Steering Gear (Sheppard) Repair
Power Steering Assist Cylinder Repair
Power Steering Pump Test Equipment Setup
Power Steering Tests and Adjustment (Ross)
Power Steering Tests and Adjustment (Sheppard)
Power Steering Gear Adjustment (On-Vehicle)
Power Steering Pump and Reservoir (M939/A1) Repair
Power Steering Pump (M939A2) Repair
4-115. GENERAL INFORMATION
The M939/A1/A2 series vehicles use one of two different models of integral power steering gears. Oil flow
from the power steering pump supplies oil pressure for both models of steering gears. Both models direct oil
flow and pressure to the same power assist cylinder mounted on the right aide of the vehicle. The two
steering gears use different pitman arms. Both types of steering gears will work manually in the event of
oil pressure failure.
ROSS STEERING GEAR. This is a recirculating ball-type steering gear with a rotary valve as the control
element. It has both a worm gear and sector shaft adjustments in addition to two adjustable poppet valves.
SHEPPARD STEERING GEAR. This is a shuttle valve and piston-type steering gear with adjustable
plungers controlling power-assisted steering angles. There are no other external mechanical adjustments.
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