GM Service Manual Online
For 1990-2009 cars only

The pinion clearance cannot be adjusted. Improper clearance is an indication of worn parts. The following procedure describes the pinion clearance inspection:

  1. Secure the starter motor in a vise or equivalent fixture so that opening in the drive end housing is accessible for measurement.
  2. Disconnect the starter motor field lead from the solenoid M terminal.
  3. Insulate the starter motor field lead from the solenoid M terminal.
  4. Caution: Keep fingers, tools, and any other objects away from the opening in the drive end housing while making electrical connections. The strong shifting action of the starter solenoid can cause severe personal injury or damage to components as the drive pinion moves into the cranking position.


    Object Number: 1038  Size: SH
  5. Connect the ground (negative) battery lead to a clean metal ground on the motor housing.
  6. Connect a 12 V battery lead to the solenoid S terminal.
  7. Notice: To prevent overheating of the solenoid pull-in winding, do not leave the winding energized for more than 15 seconds. The current draw will decrease as the winding temperature increases.

  8. Momentarily ground a jumper lead from the solenoid M terminal to the solenoid frame. This will shift the pinion into the cranking position. The pinion will remain in the cranking position until the S terminal lead is removed.
  9. Push the pinion back toward the commutator end to eliminate any free movement of the pinion on the shaft.

  10. Object Number: 1039  Size: SH
  11. Measure the distance between the pinion and the pinion stop collar using feeler gauges.
  12. The clearance should be from 0.25-4.06 mm (0.010-0.160 in).

  13. Disconnect the ground (negative) lead from the starter motor housing (the pinion will retract), then disconnect the positive lead from the solenoid S terminal.
  14. Replace the starter motor when the clearance is outside the specifications.