GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 1998 🢒 Astro - 4WD 🢒 Steering 🢒 Power Steering System 🢒 Steering Gear Pitman Shaft Over-Center Preload Adjustment - Off Vehicle

    Object Number: 322005 Size: SH
  1. Rotate the stub shaft (3) back and forth to drain the power steering fluid.
  2. Loosen the adjuster lock nut (4).
  3. Turn the pitman shaft adjuster screw (1) counterclockwise until the screw is fully extended.
  4. Turn the pitman shaft adjuster screw (1) clockwise 1 full turn.
  5. Rotate the stub shaft (3) from stop to stop using a 12-point socket while counting the number of turns.
  6. Starting at either stop, turn the stub shaft (3) back half of the total number of turns. This is the center of the gear.

    7. Object Number: 322006 Size: SH
  7. Make sure that the gear is centered by checking the following items:
    8. • The flat on the stub shaft (3) faces upward.
    • The flat on the stub shaft (3) is parallel with the side cover (2).
  8. Align the master spline (5) on the pitman shaft (4) with the adjuster screw (1).

    9. Object Number: 322007 Size: SH
  9. Place a torque wrench on the stub shaft (2) with the handle in the vertical position.
  10. Rotate the stub shaft (2) 45 degrees from each side of the center of the stub shaft. The stub shaft (2) must rotate smoothly.
  11. Record the worm bearing preload measured on or near the center (1). The recorded bearing preload must be 0.7-1.7 N·m (6-15 lb in) with the worm and the ball nut installed. If the torque is outside of this range, readjust or repair the steering gear assembly as required.

    12. Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

  12. To obtain the correct preload torque, adjust the over-center torque by turning the pitman shaft adjuster screw clockwise.
  13. Add 0.7-1.1 N·m (6-10 lb in) torque to the previously measured worm bearing preload torque.

    14. Tighten
    Tighten the adjuster lock nut to 49 N·m (36 lb ft). Prevent the adjuster screw from turning while tightening the adjuster lock nut.