GM Service Manual Online
For 1990-2009 cars only

Tools Required

J 8433 Two Jaw Puller


    Object Number: 872959  Size: SH

    Important: The following steps apply to both the 4WD and the RWD transmission, except where noted.

  1. Remove the drain plug, with aluminum washer, and drain the transmission fluid.

  2. Object Number: 880951  Size: SH
  3. If RWD, remove the vehicle speed sensor with O-ring seal.

  4. Object Number: 880943  Size: SH
  5. Remove the backup lamp switch, with the aluminum washer, from the front case.

  6. Object Number: 880652  Size: SH
  7. Remove the 9 bolts retaining the clutch housing.
  8. Using a soft-face hammer, remove the clutch housing from the transmission assembly.

  9. Object Number: 880655  Size: SH
  10. Shift the transmission into NEUTRAL.
  11. Remove the shift control housing bolts.
  12. Remove the shift control housing.
  13. Remove the shift control housing gasket.

  14. Object Number: 1526781  Size: SH
  15. Remove the shift control lever socket bolt.

  16. Object Number: 872969  Size: SH
  17. Mark the location of the brackets and the studs.
  18. Remove the extension housing retaining bolts, studs, and brackets.
  19. The 4WD does not use a bracket on the left side of the transmission.

    Notice: Refer to Machined Surface Damage Notice in the Preface section.


    Object Number: 1526783  Size: SH
  20. Using a soft-face hammer, separate the extension housing from the intermediate case.
  21. Slide the extension housing off the shift control shaft.
  22. Remove the shift control socket from the extension housing shift lever cavity.

  23. Object Number: 880657  Size: SH
  24. Remove the shift control shaft from the shift shaft gates.

  25. Object Number: 872978  Size: SH
  26. Remove the front bearing retainer bolts. Discard the bolts. New bolts are required for assembly.
  27. Remove the front bearing retainer.

  28. Object Number: 872983  Size: SH
  29. Using a suitable punch and a hammer, remove the input shaft seal from the bearing retainer. Do not use the seal again.

  30. Object Number: 872989  Size: SH
  31. Remove the outer retaining ring from the input shaft bearing.
  32. Remove the outer retaining ring from the countershaft front bearing.
  33. Notice: Refer to Machined Surface Damage Notice in the Preface section.


    Object Number: 880658  Size: SH
  34. Using a soft-face hammer on the transmission front case, shear the sealer.
  35. Remove the transmission front case from the intermediate case.

  36. Object Number: 880662  Size: SH
  37. Remove the oil baffle bolts.
  38. Remove the oil baffle.

  39. Object Number: 880663  Size: SH
  40. Remove the magnet.
  41. Notice: Refer to Machined Surface Damage Notice in the Preface section.


    Object Number: 880665  Size: SH
  42. Install 2 bolts, with nuts, in the lower holes of the intermediate case. The bolts will be used to hold the intermediate case in a vise during disassembly and assembly.

  43. Object Number: 881213  Size: SH

    Important: Before removal of the 5th synchronizer gear, measure the axial play of the speed gear. Incorrect axial play of the gear may cause shifting concerns or transmission noise.

  44. Using a feeler gage between the 5th countershaft gear and the thrust washer, measure the axial clearance.
  45. Specification

        • Standard Clearance: 0.10-0.35 mm (0.0039-0.0138 in)
        • Maximum Clearance: 0.40 mm (0.0157 in)
  46. If the clearance exceeds the maximum, refer to Gears and Shafts Cleaning and Inspection .

  47. Object Number: 880666  Size: SH
  48. Mount the intermediate case assembly in a vise on the 2 previously installed bolts.
  49. Using 2 screwdrivers and a hammer, remove the 5th synchronizer gear retaining ring.

  50. Object Number: 880668  Size: SH
  51. Using J 8433 with 2 bolts in the threaded holes of the 5th synchronizer gear, remove the gear.

  52. Object Number: 1526787  Size: SH
  53. Remove the 5th/reverse gear synchronizer.

  54. Object Number: 1526791  Size: SH
  55. Using a hammer and a punch, remove the 5th shift fork roll pin.

  56. Object Number: 1526793  Size: SH
  57. Remove the shift fork, the 5th/reverse synchronizer sleeve and blocking ring assembly and the 5th countershaft gear and bearing.

  58. Object Number: 880678  Size: SH
  59. Remove the 5th countershaft gear thrust washer.
  60. Remove the thrust washer lock pin.

  61. Object Number: 880680  Size: SH
  62. Remove the bolts for the rear bearing retainer.
  63. Remove the rear bearing retainer.

  64. Object Number: 880682  Size: SH
  65. Using a soft-face hammer, tap the countershaft rearward to expose the outer retaining ring on the countershaft rear bearing.
  66. Using a suitable prying tool on the retaining ring, remove the countershaft rear bearing. The bearing will slide out of the case if the countershaft is kept in position with the output shaft.

  67. Object Number: 880684  Size: SH
  68. Remove the countershaft.

  69. Object Number: 880685  Size: SH
  70. Remove the reverse idler gear shaft and reverse idler gear.

  71. Object Number: 880686  Size: SH
  72. Remove the input shaft assembly, with the 4th gear blocking ring, and output shaft front support bearing from the output shaft.

  73. Object Number: 880688  Size: SH
  74. Remove the 1st/2nd shift fork bolt.
  75. Remove the 3rd/4th shift fork bolt.

  76. Object Number: 880690  Size: SH
  77. Remove the retaining ring for the reverse shift lever on the reverse shift shaft.
  78. • Use a suitable pair of pliers to push the retaining ring.
    • Only push the retaining ring partially off to keep it from flying.
    • Use a pair of pliers to remove the retaining ring the rest of the way.

    Object Number: 880691  Size: SH
  79. Shift the reverse shift shaft forward.
  80. Move the reverse shift lever forward past the retaining ring groove on the reverse shift shaft. This allows clearance of the reverse shift fork during removal of the output shaft.

  81. Object Number: 880695  Size: SH
  82. Remove the output shaft rear bearing outer retaining ring.

  83. Object Number: 880697  Size: SH
  84. Remove the output shaft assembly.
  85. • Hold the 1st/2nd shift fork and the 3rd/4th shift fork in position to the output shaft.
    • Slide the 1st/2nd shift fork and the 3rd/4th shift fork off the shift shafts while removing the output shaft.

    Object Number: 880698  Size: SH

    Important: If the shift shafts or the intermediate case do not require service, proceed to Output Shaft Disassemble. If the shift shafts or intermediate case require service, proceed to the next step.

  86. Remove the 4 shift shaft detent plugs for the shift detent balls and springs. Discard the plugs. New plugs are required for assembly.

  87. Object Number: 880699  Size: SH
  88. Using a magnet, remove the 1st/2nd shift shaft detent spring and ball.
  89. Using a magnet, remove the 3rd/4th shift shaft detent spring and ball.
  90. Using a magnet, remove the 5th shift shaft detent spring and ball. The reverse shift shaft does not have a detent spring and ball in the plug opening.

  91. Object Number: 880707  Size: SH

    Important: To prevent the retaining rings from flying, cover the area with a rag.

  92. Remove the following shift shaft retaining rings:
  93. • The 1st/2nd shift shaft
    • The 3rd/4th shift shaft
    • The 5th shift shaft
       - Use a suitable pair of pliers to push the retaining ring.
       - Only push the retaining ring partially off to keep it from flying.
       - Use a pair of pliers to remove the retaining ring the rest of the way.

    Object Number: 880763  Size: SH
  94. Remove the 3rd/4th shift shaft.

  95. Object Number: 880771  Size: SH
  96. Using a magnet, remove the 1st/2nd and 3rd/4th shift shaft interlock pin.
  97. Remove the 1st/2nd shift shaft.
  98. Remove the small interlock pin from the 1st/2nd shift shaft.

  99. Object Number: 880775  Size: SH
  100. Using a magnet, remove the 5th shift shaft and 1st/2nd shift shaft interlock pin.
  101. Remove the 5th shift shaft.

  102. Object Number: 880784  Size: SH
  103. Remove the detent ball from the reverse shift lever.

  104. Object Number: 880787  Size: SH
  105. Remove the reverse shift lever, with the reverse shift fork, from the reverse shift shaft.
  106. 64.1. Slide the shift lever to the end of the shaft.
    64.2. Cover the detent ball opening with your hand.
    64.3. Let the detent ball and spring land in your hand.

    Object Number: 880791  Size: SH
  107. Using a magnet, remove the interlock pin from the reverse shift shaft. The shaft may require moving back and forth to remove the interlock pin.
  108. Remove the reverse shift shaft.

  109. Object Number: 880792  Size: SH
  110. Remove the bolts and the reverse shift fork bracket.