GM Service Manual Online
For 1990-2009 cars only

Cleaning Procedure

  1. Thoroughly wash all transmission components in clean solvent.
  2. Remove any foreign material or old lubricants.
  3. Apply compressed air to each oil feed port and channel in each case half in order to remove any obstructions or cleaning solvent residue.
  4. Notice: Do not allow the bearings to spin. Turn them slowly by hand. Spinning the bearings may damage the race and the rollers.

  5. Apply compressed air to the bearings.

Inspection Procedure

  1. Inspect the gears and the gear splines for excessive wear or damage. Remove minor nicks or scratches with an oil stone. Replace the gears if these are worn or damaged.
  2. Inspect the thrust washers for wear or damage. Replace the thrust washers if these are worn or damaged.
  3. Inspect the clutch and the two halves of the differential case. Replace any part that has the following conditions:
  4. • Cracks
    • Porosity
    • Damaged mating surfaces
    • Stripped bolt threads
    • Distortion

    Important: Lubricate the bearings with a light oil.

  5. Inspect the condition of all the needle, the roller, and the thrust bearings.
  6. Important: The synchronizer hubs and the sliding sleeves are a selected assembly and these should be kept together as originally assembled.

  7. Clean the synchronizer components with clean solvent. Air dry the components.
  8. Inspect the synchronizer teeth for the following conditions:
  9. • Wear
    • Scuffing
    • Nicks
    • Burrs
    • Breaking
  10. Inspect the synchronizer keys and the springs for the following conditions. Replace the keys or the springs if the following conditions exist:
  11. • Wear
    • Cracks
    • Distortion
  12. If scuffed, nicked or burred conditions cannot be corrected with a soft stone or crocus cloth, replace the component.

  13. Object Number: 12513  Size: SH
  14. Measure the clearance between the blocker ring and the inserts. Replace the components if these are not within the following specifications:
  15. • 1st/2nd gear--3.9 mm (0.154 in) or less
    • 3rd/4th and 5th gear--3.7 mm (0.146 in) or less

    Object Number: 12514  Size: SH
  16. Measure the clearance between the blocker ring and the gear. Replace the component if the measurement is less than 0.8 mm (0.031 in).

  17. Object Number: 12515  Size: SH
  18. Measure the clearance between the blocker ring and the synchronizer cones. Replace the 1st/2nd synchronizer components if the measurement exceeds 0.8 mm (0.031 in).
  19. When assembling the synchronizer assemblies, make sure that each insert spring supports all three of the keys. Also, make sure that each opening portion of the insert spring faces the opposite direction from each other.

  20. Object Number: 12516  Size: SH
  21. Inspect the detent springs for damage or wear. Replace the springs if damage or wear exists. Measure the spring length. Replace the spring if these are not within the following specifications:
  22. • Reverse--Greater than 65.6 mm (2.583 in)
    • Except reverse--Greater than 26.2 mm (1.031 in)

    Object Number: 12517  Size: SH
  23. Inspect the shift forks, the shafts, and the levers for wear or damage. Replace these if the conditions exist. Measure the shift fork pad thickness. Replace the shift fork pad if the pad is thinner than the following specifications:
  24. • Reverse--7.4 mm (0.291 in)
    • Except reverse--7.5 mm (0.295 in)