GM Service Manual Online
For 1990-2009 cars only

Tools Required

    • DT-48209 Bushing Remover
    • J 3289-20 Holding Fixture
    • J 8092 Driver Handle
    • J 22912-B Split-Plate Bearing Puller
    • J 23907 Slide Hammer with Bearing Adapter
    • J 26941 Bushing and Bearing Remover - 3-4 inch
    • J 45380 Transfer Case Rear Bushing Remover and Installer
    • J 45759 Assembly Fixture

    Object Number: 824069  Size: SH

    Important: 

       • The following service procedure covers light duty (LD), heavy duty (HD), and super heavy duty (SHD) versions of this transfer case.
       • The front output shaft seal and the input shaft seal only require replacement if faulty, or if removing the front output shaft or input gear.

  1. Attach the J 45759 to the transfer case using the adapter studs. All of the transfer case disassembly procedures can be performed with the case mounted to the J 45759 .

  2. Object Number: 819573  Size: SH
  3. Mount the J 3289-20  (1) to a sturdy workbench.
  4. Install the J 45759  (2) into J 3289-20  (1) and secure with pivot pin.

  5. Object Number: 715670  Size: SH
  6. Remove the rear output shaft seal.

  7. Object Number: 801274  Size: SH
  8. Inspect the rear output shaft bushing for scoring or wear.
  9. Important: The J 45380 does not work on the SHD version of the transfer case. Review step 72 if removal of the SHD rear output shaft bushing is required.

  10. LD and HD only - Remove the rear output shaft bushing using the J 45380 .
  11. • Install the finger section of the J 45380 in front of the bushing.
    • Install the tube and forcing screw assembly to the finger section. Ensure the forcing screw is backed out.
    • Using a wrench on the forcing screw, remove the rear output shaft bushing.

    Object Number: 394338  Size: SH
  12. Remove the access hole plug.

  13. Object Number: 394335  Size: SH
  14. Remove the transfer case vehicle speed sensor.

  15. Object Number: 662850  Size: SH
  16. Remove the encoder motor mounting bolts.
  17. Remove the encoder motor assembly.
  18. Remove the actuator insulator gasket.

  19. Object Number: 887077  Size: SH
  20. Remove the plastic vent from the case; a NEW aluminum vent must be installed during assembly.

  21. Object Number: 163727  Size: SH
  22. Remove the transfer case retaining bolts or studs, the washers, and the brackets.
  23. Mark the location of the brackets and studs for correct assembly.

  24. Object Number: 695581  Size: SH
  25. Insert a screwdriver into the slot on the left side of the transfer case.

  26. Object Number: 695583  Size: SH
  27. Insert a screwdriver into the slot on the right side of the transfer case.
  28. With equal pressure applied on each screwdriver, separate the front half and the rear half.

  29. Object Number: 649760  Size: SH
  30. Using snap ring pliers, release the outside retaining ring for the rear output shaft bearing.

  31. Object Number: 163737  Size: SH
  32. Remove the rear case half from the front case half.

  33. Object Number: 701586  Size: SH
  34. Remove the rear output shaft bearing retaining ring.

  35. Object Number: 701589  Size: SH
  36. Remove the rear output shaft bearing.

  37. Object Number: 722014  Size: SH

    Important: The super heavy duty (SHD) model transfer case does not use a retaining ring for the speed reluctor wheel. If a heavy duty transfer case model has been reconditioned using the new design rear output shaft, the speed reluctor wheel retaining ring will not be used.

  38. Remove the speed reluctor wheel retaining ring, if used.

  39. Object Number: 701592  Size: SH
  40. Remove the speed reluctor wheel.

  41. Object Number: 163872  Size: SH
  42. Remove the oil pump suction pipe from the oil pump assembly.
  43. Remove the oil pump screen from the front case half.
  44. Disconnect the connector between the oil pump suction pipe to the oil pump screen.

  45. Object Number: 163856  Size: SH
  46. Remove the magnet.

  47. Object Number: 701595  Size: SH
  48. Remove the oil pump assembly.

  49. Object Number: 163888  Size: SH
  50. Remove the O-ring seal for the oil pump suction pipe.

  51. Object Number: 391103  Size: SH

    Important: The super heavy duty (SHD) model transfer case does not use an oil pump O-ring seal. If a heavy duty transfer case model has been reconditioned using the new design rear output shaft, the oil pump O-ring seal will not be used.

  52. Remove the oil pump O-ring seal, if used.

  53. Object Number: 391094  Size: SH
  54. Remove the shift fork shaft spring.

  55. Object Number: 701619  Size: SH
  56. Remove the driven sprocket retaining ring.

  57. Object Number: 701617  Size: SH
  58. Remove the drive sprocket retaining ring.

  59. Object Number: 163905  Size: SH

    Important: If the drive chain and sprockets are to be used again, mark the position of the drive chain to the drive sprockets, in order to ensure that any wear patterns will be matched for proper installation.

  60. Remove the drive chain and the sprockets from the rear output shaft and the front output shaft.

  61. Object Number: 812456  Size: SH
  62. Remove the 2/4 wheel drive synchronizer gear from the drive sprocket sleeve.

  63. Object Number: 887080  Size: SH

    Important: Remove the rear output shaft as an assembly with the synchronizer and the shift fork.

  64. Remove the rear output shaft with the shift fork. The shift shaft can remain in the case.
  65. Remove the 2/4 wheel drive mode shift fork from the synchronizer assembly.

  66. Object Number: 812457  Size: SH
  67. Mount the rear output shaft in a soft-jaw vise with the input end up.
  68. Remove the synchronizer assembly retaining ring.

  69. Object Number: 812459  Size: SH
  70. Remove the synchronizer as an assembly.
  71. Remove the synchronizer outer ring, middle ring, and inner ring.

  72. Object Number: 392293  Size: SH
  73. Remove the front retaining ring for the drive sprocket from the drive sprocket sleeve.
  74. Remove the drive sprocket sleeve from the rear output shaft.

  75. Object Number: 812463  Size: SH
  76. If necessary, disassemble the synchronizer assembly.
  77. • Remove the inner ring (1).
    • Remove the middle ring (2).
    • Remove the outer ring (3).
    • Remove the synchronizer sleeve (4) from the hub (6).
    • Remove both insert springs (5 and 8) from the hub.
    • Remove the inserts (7).

    Object Number: 164548  Size: SH
  78. Remove the shift detent spring bolt and O-ring seal.
  79. Remove the shift detent spring and the plunger.

  80. Object Number: 812460  Size: SH
  81. Remove the shift shaft from the high/low range fork and the front case.

  82. Object Number: 812461  Size: SH
  83. Remove the high/low range sleeve and the shift fork.

  84. Object Number: 812462  Size: SH
  85. Remove the range sleeve from the shift fork.

  86. Object Number: 742094  Size: SH
  87. Disassemble the range fork assembly, if necessary, for inspection.

  88. Object Number: 393280  Size: SH
  89. Remove the input shaft seal.

  90. Object Number: 701644  Size: SH
  91. Remove the outer retaining ring for the input gear bearing.

  92. Object Number: 393284  Size: SH
  93. Remove the high/low planetary carrier.

  94. Object Number: 165318  Size: SH
  95. Remove the retaining ring for the input gear.

  96. Object Number: 165308  Size: SH
  97. Remove the planetary carrier lock plate.

  98. Object Number: 165300  Size: SH
  99. Remove the planetary carrier front thrust washer.

  100. Object Number: 165294  Size: SH
  101. Remove the input gear.

  102. Object Number: 165286  Size: SH
  103. Remove the planetary carrier rear thrust washers.

  104. Object Number: 165322  Size: SH
  105. Inspect the needle bearing in the input gear for being faulty. Refer to Transfer Case Cleaning and Inspection .
  106. Remove the needle bearing from the input gear using a brass drift and a hammer, if faulty.

  107. Object Number: 393324  Size: SH

    Important: For the super heavy duty version of the NVG 263, it may be necessary to rotate the bearing in the front case in order to gain access to the retaining ring.

    When removing the retaining ring for the input shaft bearing in the super heavy duty version of the NVG 263, the retaining ring must be fully expanded; then remove the input shaft bearing. DO NOT release the retaining ring until the input shaft bearing has been removed.

  108. Remove the input gear bearing retaining ring.
  109. Remove input gear bearing.

  110. Object Number: 895747  Size: SH
  111. Remove the inner retaining ring for the front output shaft bearing.

  112. Object Number: 895089  Size: SH
  113. Using a soft-face hammer, remove the front output shaft, with the bearing, from the front case half.

  114. Object Number: 895092  Size: SH
  115. Using a suitable punch, remove the front output shaft seal from the front case half.

  116. Object Number: 895751  Size: SH
  117. Remove the outer retaining ring for the front output shaft bearing.

  118. Object Number: 895754  Size: SH
  119. Inspect the front output shaft bearing for being faulty. Refer to Transfer Case Cleaning and Inspection .
  120. Remove the bearing from the front output shaft. Do not use the bearing again after removal.

  121. Object Number: 165060  Size: SH
  122. If the cup plug in the front output shaft is leaking, remove the plug using a brass drift.

  123. Object Number: 801288  Size: SH
  124. Inspect the front output shaft rear bearing for being faulty. Refer to Transfer Case Cleaning and Inspection .
  125. If the bearing is faulty, remove the bearing using the J 23907  (2) and the J 26941  (1).

  126. Object Number: 1868945  Size: SH
  127. SHD only - Remove the rear output shaft bushing using the J 8092  (1) and DT-48209  (2) .

  128. Object Number: 702170  Size: SH
  129. Remove the shift detent lever retaining ring.

  130. Object Number: 393275  Size: SH
  131. Remove the shift detent lever shaft.
  132. Inspect the shift detent lever bearing and seal for being faulty. Refer to Transfer Case Cleaning and Inspection .
  133. If the seal or bearing is faulty, remove the bearing from the case.