GM Service Manual Online
For 1990-2009 cars only

Special Tools

    • J 33013-B Hub and Drive Plate Remover/Installer
    • J 33022 6 Shaft Nut Socket - 13 mm - 6 pt
    • J 33027-A A/C Clutch Hub Holder
    • J 34992 Compressor Holding Fixture

Disassembly Procedure


    Object Number: 1256087  Size: SH
  1. Remove the compressor. Refer to Air Conditioning Compressor Replacement.
  2. Install the J 34992  (1) to the compressor and hold the compressor holding fixture using a bench vise.
  3. Use the J 33027-A  (3) to keep the clutch drive plate and the hub assembly from turning.
  4. Remove the shaft nut using the J 33022  (2).

  5. Object Number: 1256088  Size: SH
  6. Thread the hub and J 33013-B  (1) into the hub. Hold the body of the remover with a wrench and turn the center screw into the remover body to remove the clutch drive plate and the hub assembly.
  7. Remove the clutch hub key. Retain the key for assembly.

Assembly Procedure


    Object Number: 1251986  Size: SH
  1. Install the clutch hub key into the hub keyway. Allow the key to project approximately 3.2 mm (1/8 in) out of the keyway. The hub key is curved slightly to provide an interference fit in the hub key groove.
  2. Be sure the frictional surface of the clutch plate and the pulley rotor are clean before installing the clutch drive plate and the hub assembly.
  3. Caution: Use the proper installation tool to reinstall the clutch plate to hub. Do not use force to install. The use of force may cause internal damage to compressor.

  4. Align the clutch hub key with the shaft keyway. Place the clutch drive plate and the hub assembly onto the compressor shaft.

  5. Object Number: 1256088  Size: SH
  6. Remove the J 33013-B  (1) center bolt and reverse the body direction on the center bolt. The body of the J 33013-B should be backed off sufficiently to allow the center bolt to be threaded onto the end of the compressor shaft.
  7. Note: If the center bolt is threaded fully onto the end of the compressor shaft, or if the body of the J 33013-B is held and the center bolt is rotated, the key will wedge and could break the clutch drive plate and the hub assembly.

  8. Install the J 33013-B (1) and the bearing onto the clutch drive plate. Thread the center bolt onto the compressor shaft.
  9. Hold the center bolt with a wrench. Tighten the hex portion of the J 33013-B (1) body to press the hub onto the shaft. Tighten the body several turns.
  10. Remove the J 33013-B (1) and check to see that the clutch hub key is still in place in the keyway before installing the clutch drive plate and the hub assembly to its final position.
  11. Specification
    The air gap between frictional surfaces of the clutch drive plate and the clutch pulley rotor should be 0.38-0.64 mm (0.015-0.025 in).


    Object Number: 1256087  Size: SH
  12. Remove the J 33013-B . Check for proper positioning of the clutch hub key. It should be even or slightly above the clutch hub.
  13. Caution: Refer to Fastener Caution in the Preface section.

  14. Install the shaft nut. Hold the clutch drive plate and the hub assembly with the J 33027-A  (3). Use the J 33022  (2) and tighten the nut against the compressor shaft shoulder to 17 N·m (13 lb ft).
  15. Spin the pulley rotor by hand to verify that the pulley is not rubbing the clutch drive plate.
  16. Remove the compressor from the bench vise and remove the J 34992  (1) from the compressor.
  17. Install the compressor. Refer to Air Conditioning Compressor Replacement.