Over-Center Preload

With worm bearing preload adjusted, turn worm shaft slowly from stop-to-stop while counting total number of turns. Turn shaft back to the exact center position.
Loosen lock nut and turn sector shaft adjuster screw (located in center of sector shaft cover) in until all lash is taken out of sector shaft. Tighten lock nut. Rotate worm shaft slightly off center then attach an INCH lb. torque wrench to worm shaft or steering wheel nut.
Rotate worm shaft back through center position and note rotating torque. Rotating torque should be 4-10 INCH lbs. (.5-1.1 N.m) in excess of worm bearing preload. Maximum torque should not exceed 16 INCH lbs. (1.8 N.m). If rotating torque is not within specification, adjust sector shaft adjuster screw.

CAUTION: If maximum torque is exceeded, rotate sector shaft adjuster screw counterclockwise, and adjust by rotating lock nut clockwise.

Fig 1: Exploded View of Steering Gear

Courtesy of GENERAL MOTORS CORP.

NOTE: Replacement fasteners must have the same part numbers as originals. Torque all fasteners and install NEW cotter pin.