Poppet Adjustment


Auto Poppet Adjustment for TAS, THP, Sheppard M-Series with Auto Poppets (Part Number Ending in 3) and ZF Series Steering Gear

This remanufactured steering gear has had the poppet valves reset. DO NOT turn the steering gear more than 1-1/2 turns right or left of center until step one in completed.

  1. The axle stops and all steering linkage must be set according to the vehicle manufacturer's specifications, and the pitman arm must be correctly aligned on the sector shaft and draglink installed for poppets to be set correctly.
  2. Raise front end so tires are just off the ground. Make  sure pump reservoir is full of fluid.
  3. With the engine at idle, turn the steering wheel to full travel in one direction until axle stop contact is made. Pull steering wheel to the stop hard. Maximum input  torque applied during this procedure is 40 lb. rim pull on a 20 in. diameter steering wheel.
  4. Follow the same procedure while turning the steering wheel in the other direction. The poppets are now positioned to trip and reduce pressure as the steered wheels approach the axle stops in either direction.

Manual Relief Valve Poppet Adjustment for HF, HFB, Sheppard 292, 392, 492, 592, M-Series with Manual Poppets

Should you need to adjust MANUAL relief valve plungers, use the following procedures:

  1. Allow engine to operate at idle speed. With full weight of vehicle on all wheels, turn steering wheel in one direction until a high pressure hiss is heard or axle stops contact. Return tires to straight ahead position.
  2. Turn relief valve plunger in or out until  he high pressure hiss is heard when there is 1/8" to 3/16" clearance between axel stops. Do not adjust plunger with pressure on the steering wheel. Seal damage can result.
  3. Repeat this procedure for the opposite direction of steer.
  4. Turning plunger in will increase space between axle stops. urning plunger out will decrease clearance between axle stops. Do not turn slotted plunger out beyond flush with plunger boss or a leak will occur.
  5. After relief valve plunger adjustment, always check that wheels and tires have adequate clearance between suspension, brake and frame components.

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