GM Service Manual Online
For 1990-2009 cars only

Tools Required

J 45012 Holding Fixture


    Object Number: 820772  Size: SH
  1. Place the rear housing in a vice.
  2. Notice: Do not heat the component over the specified value or damage could occur.

  3. Heat the inner race of the roller bearing to 80°C (176°F).

  4. Object Number: 820774  Size: SH
  5. Move the synchromesh rings into reverse and 2nd gear positions.
  6. Important: The 3rd/4th shift shaft will be installed later in the assembly process.

  7. Install all shift forks except the 3rd/4th to their respective synchromesh rings, the 5th/reverse and the 1st/2nd, with their shafts.
  8. Assemble the main drive gear and counter gear to the mainshaft assembly, holding everything together as a single assembly.

  9. Object Number: 820777  Size: SH
  10. While the inner race is hot, install the mainshaft, counter gear and shift forks as an assembly into the rear housing.
  11. Inspect to ensure that all shift forks are seated in their bores.

  12. Object Number: 779389  Size: SH
  13. Install the interlock pin (2) into the 3rd/4th shift shaft (1), then push the shift shaft trough the housing into the shift fork.
  14. Install plug (3) into the rear housing hole.

  15. Object Number: 820779  Size: SH
  16. Support the shift fork and install a new roll pin through the shift fork and shaft.

  17. Object Number: 1738948  Size: SH
  18. Install the reluctor wheel to the rear case section.

  19. Object Number: 1738944  Size: SH
  20. Install the seal to the rear case section.

  21. Object Number: 820781  Size: SH
  22. Install the rear flange and nut.
  23. Notice: Refer to Fastener Notice in the Preface section.

  24. Use J 45012  (2) to hold the rear flange while tightening the nut (1).
  25. Tighten
    Torque the flange nut to 100 N·m (74 lb ft). This will seat the mainshaft into the bearing.


    Object Number: 779394  Size: SH
  26. Install the reverse idler gear (4) into the rear housing.
  27. Install the reverse idler shaft and bearings (3).
  28. Install the reverse idler shaft retaining bolt, and hand tighten.
  29. Align the thrust plate (2) with the groove on the reverse idler gear, and install the thrust plate retaining bolt (1).
  30. Tighten
    Hold the reverse idler gear up to the thrust plate and tighten the retaining bolt to 25 N·m (18 lb ft).


    Object Number: 820783  Size: SH
  31. Apply a thin coating of petroleum jelly to the gearshift operating shaft pins (6) and rollers (5), and install onto the shift shaft (4).
  32. Install the shift shaft seal (3) into the rear housing.
  33. Install the shift shaft (4) through the hole in the rear housing, and slide into the gearshift selector arm (1).
  34. Align the roll pin hole in the selector arm (1) with the hole in the shift shaft (4) and install the roll pin (2).

  35. Object Number: 779379  Size: SH
  36. Install the 3 detent balls (1) and springs (2) into the rear housing.
  37. Install cover (3) and bolts (4).
  38. Tighten
    Tighten the cover bolts to 10 N·m (7 lb ft).


    Object Number: 1741475  Size: SH

    Notice: Do not heat the component over the specified value or damage could occur.

  39. Heat the inner race of the front case's ball bearing assembly to 80°C (176°F).

  40. Object Number: 779341  Size: SH
  41. Apply a bead of LOCTITE 574 sealant or equivalent to the rear housing sealing surface.
  42. Position the front housing onto the rear housing, aligning shift rods with the bores in the front housing.

  43. Object Number: 779367  Size: SH

    Important: While the front housing and the rear housing are together, have an assistant pull on the main shaft while tapping the inner race down with a hammer and punch to fully seat. Take care not to damage the bearing.

  44. Install the long housing bolt (1) in the correct position as shown.
  45. Install the remaining housing bolts and tighten in a criss cross pattern.
  46. Tighten
    Tighten all housing bolts to 25 N·m (18 lb ft).


    Object Number: 779346  Size: SH
  47. Install the spacer (2) and snap ring (1) onto the mainshaft.

  48. Object Number: 779337  Size: SH
  49. Install CSC assembly (2) and O-ring (3), with the 3 bolts (1) and bolt (5).
  50. Tighten
    Tighten the CSC assembly bolts (1) to 20 N·m (15 lb ft) and bolt (5) to 10 N·m (7 lb ft).


    Object Number: 779348  Size: SH
  51. Install the speed sensor (1) and bolt (2).
  52. Tighten
    Tighten the speed sensor bolt to 10 N·m (7 lb ft).


    Object Number: 779357  Size: SH
  53. Apply sealant GM P/N 12346004, (Canadian P/N 10953480), to the threads of the reverse switch.
  54. Install the reverse switch into the rear housing.
  55. Tighten
    Tighten the reverse switch to 18 N·m (13 lb ft).


    Object Number: 779365  Size: SH
  56. Install the reverse idler bolt (1) into the front housing.
  57. Tighten
    Tighten the reverse idler bolts to 25 N·m (18 lb ft).


    Object Number: 779360  Size: SH
  58. Install the detent pin (1), spring (2) and plug (3) into the front housing.

  59. Object Number: 820785  Size: SH
  60. Apply pipe sealant GM P/N 1052080, (Canadian P/N 10953480), or equivalent to the drain plug threads.
  61. Install the drain plug.
  62. Tighten
    Tighten the drain plug to 35 N·m (26 lb ft).

  63. Fill the transmission with 3.27L (2.9 qt) of DEXRON III GM P/N 12346143, (Canadian P/N 10952622), after installation in the vehicle.
  64. Apply pipe sealant GM P/N 1052080, (Canadian P/N 10953480), or equivalent to the fill plug threads.
  65. Install the drain plug.

    Tighten
    Tighten the fill plug to 35 N·m (26 lb ft).