GM Service Manual Online
For 1990-2009 cars only

Tools Required

    • J 22912-B Split Plate Bearing Puller
    • J 36513 Gear and Bearing Separator Plate
    • J 44707 T-Bar Push Puller
    • J 44749 Split Plate Bearing Gear Puller
    • J 44759 Adapter 3/8 NC to 5/8 NF

    Object Number: 789394  Size: SH

    Important: For installation alignment scribe an alignment mark on the synchronizer hubs and synchronizer sleeves before removing. To prevent the synchronizer springs and struts from being lost, do not separate the synchronizer hubs from the synchronizer sleeves. Keep the synchronizer clutch gear and the blocking rings with the synchronizer hubs. Organize the components in order to install the components in their original location and position.

  1. Position the mainshaft assembly in a soft jaw vise for ease of disassembly.
  2. Remove the 4th speed gear clutch gear.
  3. Remove the 4th speed gear synchronizer ring.

  4. Object Number: 102279  Size: SH
  5. Remove the main drive gear thrust bearing.

  6. Object Number: 789395  Size: SH
  7. Using the J 44707  (1), the J 44759  (2), and the J 36513  (3), remove the 3rd/4th synchronizer hub from the mainshaft with the 3rd speed gear.
  8. • Position the J 36513  (3) behind 3rd gear.
    • A hydraulic press with a large bearing splitter can also be used.

    Object Number: 100573  Size: SH
  9. Remove the 3rd speed gear bearing.
  10. Remove the mainshaft bearing spacer.

  11. Object Number: 827700  Size: SH

    Important: The wear of the 1st and 2nd speed synchronizer can only be measured correctly while the synchronizer and the speed gears are installed on the mainshaft. The synchronizer uses a fixed inner cone.

  12. In order to measure the wear gap for the 1st speed gear position, perform the following:
  13. 8.1. Engage the 1st/2nd synchronizer sleeve in the 2nd speed gear position.
    8.2. Move the sleeve, with light, even, pressure towards 1st gear. The inserts will press against the blocker ring.
    8.3. Insert the feeler gage between the synchronizer hub and the blocker ring to measure the wear gap.

    The 1st speed synchronizer wear gap is 1.37-0.31 mm (0.054-0.012 in).


    Object Number: 827699  Size: SH
  14. In order to measure the wear gap for the 2nd gear position, perform the following:
  15. 9.1. Engage the 1st/2nd synchronizer sleeve in the 1st speed gear position.
    9.2. Move the sleeve, with light, even, pressure towards 2nd gear. The inserts will press against the blocker ring.
    9.3. Insert the feeler gage between the 2nd gear clutch teeth and the blocker ring to measure the wear gap.

    The 2nd speed synchronizer wear gap is 2.16-1.14 mm (0.085-0.045 in).


    Object Number: 100575  Size: SH
  16. Remove the 2nd speed gear thrust washer retainer ring.
  17. Remove the 2nd speed gear thrust washer.
  18. Remove the 2nd speed gear thrust washer retaining pin.

  19. Object Number: 102272  Size: SH
  20. Remove the 2nd speed gear.

  21. Object Number: 100577  Size: SH
  22. Remove the 2nd speed gear bearing.

  23. Object Number: 789396  Size: MH

    Important: For installation alignment scribe an alignment mark on the synchronizer hubs and synchronizer sleeves before removing. To prevent the synchronizer springs and struts from being lost, do not separate the synchronizer hubs from the synchronizer sleeves. Keep the synchronizer clutch gear and the blocking rings with the synchronizer hubs. Organize the components in order to install the components in their original location and position.

  24. Remove the following 1st/2nd gear synchronizer components:
  25. 15.1. The 2nd speed gear synchronizer outer ring retaining ring front (1)
    15.2. The 2nd speed gear synchronizer inner ring (2)
    15.3. The 2nd speed gear synchronizer center ring (4)
    15.4. The 2nd speed gear synchronizer outer ring (5)
    15.5. The 2nd speed gear synchronizer outer ring retaining ring rear (3)
    15.6. The 1st/2nd speed synchronizer assembly (6)
    15.7. The 1st speed gear synchronizer outer ring (7)
    15.8. The 1st speed gear synchronizer center ring (8)
    15.9. The 1st speed gear outer ring retaining ring front (9)
    15.10. The 1st speed gear synchronizer inner ring (10)
    15.11. The 1st speed gear synchronizer outer ring retaining ring rear (11)

    Object Number: 789397  Size: SH
  26. Using a hydraulic press and the J 44749 or equivalent, remove the rear mainshaft bearing. Use the J 44749 under the reverse gear.

  27. Object Number: 789398  Size: SH
  28. Remove the rear mainshaft bearing.
  29. Remove the reverse gear thrust washer.
  30. Remove the reverse gear.

  31. Object Number: 789400  Size: SH
  32. Remove the reverse gear bearing.
  33. Remove the mainshaft gear spacer.

  34. Object Number: 789402  Size: SH
  35. Remove the retainer ring for the reverse gear clutch hub.
  36. Remove the reverse gear clutch hub and the synchronizer ring.

  37. Object Number: 789404  Size: SH
  38. Remove the 1st speed gear.
  39. Remove the 1st speed gear bearing.