Levy Steering

Troubleshoot your power steering problems with our DIGITAL MECHANIC

Poppet Adjustment
TRW / Ross & Sheppard Steering Gears

HF, HFB, 292, 392, 492, 592, M-Series
The relief valve plunger adjustment is provided to automatically reduce the steering pressure when the road wheels have reached their limits of turn. This keeps the supply pump from operating at its maximum relief pressure when the road wheels are at their steering limits. System temperatures are therefore reduced and high stress loads on the mechanical components of the steering system are relieved.

High pressure oil at either end of the piston will push the relief ball valve off its seat and fill the relief passage with oil at high pressure. At the opposite end of its passage the relief ball valve is held against the seat and holds the high pressure in the relief passage. As the piston moves close to its limits of stroke, the adjustable relief plungers push the relief ball off its seat and the pressure is relieved. The distance the piston can move is dependent upon the total front axle/steering system geometry and tire size. The relief valve plungers are adjustable to allow for variations or changes in these areas.

Adjustment procedure

  1. Start engine and allow it to run at idle speed

  2. With full weight of vehicle on all wheels, turn the steering wheel in one direction until a high-pressure hiss is heard or the axle stops contact

  3. Turn the relief plunger in or out until the high-pressure hiss is heard when there is 1/8 to 3/16 inch clearance between the axle stops

  4. Repeat this procedure for the opposite direction of steer, and adjust the relief valve plunger on the opposite end of the steering gear. Axle stops should only be adjusted in accordance with the vehicle manufacturer's specifications.

TAS40, TAS55, TAS65, TAS85
All TAS series gears are equipped with self adjusting poppets which are set once the unit is mounted to a vehicle.

Adjustment procedure

  1. With the engine at idle and the vehicle unloaded, turn the steering wheel toward full travel in one direction until the steering gear linkage fully bottoms against the axle stops. Maximum input torque is 25 ft. lbs. or 30 lbs. rim pull on a 20 in. dia. steering wheel. This will automatically position the poppet adjuster seat and sleeve assembly

  2. Follow the same procedure while turning the steering wheel in the other direction

back to Troubleshooting