GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2000 🢒 Astro - 4WD 🢒 Driveline/Axle 🢒 Transfer Case - NVG 136-NP4 (One Speed Automatic) 🢒 Transfer Case Disassemble
    • J 3289-20 Holding Fixture
    • J 23907 Slide Hammer with Bearing Adapter
    • J 26941 Bushing and Bearing Remover - 3-4 in
    • J 45380 Transfer Case Rear Bushing Remover and Installer
    • J 45759 Assembly Fixture

    Object Number: 824069 Size: SH
  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
  2. Mount the J 3289-20  (1) to a sturdy workbench.
  3. Install the J 45759  (2) into J 3289-20  (1) and secure with pivot pin.

    4. Object Number: 165441 Size: SH
  4. Remove the drain and fill plugs.
  5. Drain the fluid from the transfer case.

    6. Object Number: 670238 Size: SH
  6. Remove the encoder motor mounting bolts.
  7. Remove the encoder motor assembly.
  8. Remove the encoder motor gasket.

    9. Object Number: 163714 Size: SH
  9. Remove the left rear speed sensor.
  10. Remove the right rear speed sensor.

    11. Object Number: 163707 Size: SH
  11. Remove the front speed sensor.

    12. Object Number: 163610 Size: SH
  12. Remove the vent tube, only if it is damaged.

    13. Object Number: 163722 Size: SH
  13. Remove the rubber plug.

    14. Notice: Refer to Transfer Case Seal Removal Notice in the Preface section.


    Object Number: 705377 Size: SH
  14. Remove the front output shaft seal.

    15. Notice: Refer to Transfer Case Seal Removal Notice in the Preface section.


    Object Number: 678215 Size: SH
  15. Remove the input shaft seal.

    16. Notice: Refer to Transfer Case Seal Removal Notice in the Preface section.


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

    17. Object Number: 801274 Size: SH
  17. Inspect the rear bushing for scoring or wear.
  18. Using the J 45380 , remove the rear bushing.
    19. • 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 bushing.

    Object Number: 163733 Size: SH
  19. Remove the transfer case retaining bolts and studs.
  20. Mark the location of the studs and brackets.

    21. Object Number: 695581 Size: SH
  21. Insert a flat bladed screwdriver in the slot on the left side of the transfer case.

    22. Object Number: 695583 Size: SH
  22. Insert a flat bladed screwdriver in the slot on the right side of the transfer case.
  23. Apply equal pressure on both of the screwdrivers, in a downward motion, and separate the front and rear case halves.

    24. Object Number: 649760 Size: SH
  24. Insert snap ring pliers in the slot.
  25. Using the snap ring pliers, open the retaining ring for the rear output shaft bearing.

    26. Object Number: 163737 Size: SH
  26. Remove the rear case from the front case.

    27. Object Number: 724251 Size: SH
  27. Remove the oil pump wear sleeve, only if it is worn or damaged.

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

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

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

    31. Object Number: 892466 Size: SH

    Important: The rear output shaft may be an original design (2) or the replacement design (1). The original design rear output shaft (2) uses an oil pump wave washer above the oil pump and a retaining ring under the oil pump. The original design rear output shaft (2) is identified by the splines in the area by the oil gallery hole. The replacement design rear output shaft has a smooth area by the oil gallery hole.

  31. Inspect the rear output shaft to identify as an original design (2) or the replacement design (1).

    32. Object Number: 701594 Size: SH
  32. Remove the oil pump wave spring, if original design rear output shaft.

    33. Object Number: 163856 Size: SH
  33. Remove the magnet.

    34. Object Number: 163872 Size: SH
  34. Remove the oil pump screen assembly.

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

    36. Object Number: 163888 Size: SH
  36. Remove the oil pump pick up tube seal.

    37. Object Number: 163898 Size: SH
  37. Remove the oil pump retaining ring, if original design rear output shaft.

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

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

    40. Object Number: 163905 Size: SH

    Important: If the drive chain and sprockets are to be used again, mark the relationship of the drive chain to the sprockets for proper alignment of the wear pattern.

  40. Remove the drive chain and sprockets.

    41. Object Number: 701622 Size: SH
  41. Remove the rear output shaft assembly.
  42. Mount the rear output shaft in a soft-jaw vise with the input end up.

    43. Object Number: 164262 Size: SH
  43. Remove the clutch retaining ring.

    44. Object Number: 801276 Size: SH
  44. Remove the clutch pressure plate assembly.
  45. Remove the clutch pressure plate spring.

    46. Object Number: 801280 Size: SH
  46. Remove the clutch pressure plate bearing along with the clutch pressure plate hub, from the clutch pressure plate.

    47. Object Number: 801281 Size: SH
  47. Inspect the bearing for being faulty. Refer to Transfer Case Cleaning and Inspection .
  48. If the bearing is faulty, using a hydraulic press and a suitable adapter, remove the clutch pressure plate bearing from the clutch pressure plate hub.
  49. Discard the bearing after removal.

    50. Object Number: 163895 Size: SH
  50. Remove the clutch hub retaining ring.

    51. Object Number: 801282 Size: SH
  51. Remove the clutch housing and hub assembly from the rear output shaft.
  52. Remove the clutch hub oil restrictor plate.

    53. Object Number: 801283 Size: SH
  53. Turn the clutch assembly over on a workbench.
  54. Remove the clutch housing.
  55. Remove the clutch hub.
  56. Remove the clutch backing plate.

    57. Object Number: 892510 Size: SH

    Important: Do not wash the clutch inner friction plates in cleaning solvent.

  57. Separate the clutch plates for inspection.
  58. Remove and discard the shim or shims.

    59. Object Number: 164507 Size: SH
  59. Remove the oil restrictor from the rear output shaft, if replacing the shaft.

    60. Object Number: 165429 Size: SH
  60. Inspect the bearing in the clutch housing for being faulty. Refer to Transfer Case Cleaning and Inspection .
  61. If the bearing is faulty, use a brass drift and a hammer to remove the bearing.

    62. Object Number: 701623 Size: SH
  62. Remove both of the clutch lever pivot pins with washers and O-ring seals.

    63. Object Number: 164548 Size: SH
  63. Remove the shift detent spring bolt.
  64. Remove the following components:
    65. • The shift detent plunger plug O-ring seal
    • The shift detent spring
    • The shift detent plunger

    Object Number: 701627 Size: SH
  65. Remove the clutch lever assembly.

    66. Object Number: 701644 Size: SH

    Important: Do not scratch the oil seal surface of the input shaft with the retaining ring.

  66. Remove the input shaft retaining ring.

    67. Object Number: 701631 Size: SH
  67. Remove the input shaft bearing retaining ring.

    68. Object Number: 701634 Size: SH
  68. Remove the input shaft assembly.

    69. Object Number: 701640 Size: SH
  69. Remove the input shaft bearing. Do not use the bearing again after removal.

    70. Object Number: 164440 Size: SH
  70. Using a brass drift, remove the input gear pilot bearing. Do not use the bearing again after removal.

    71. Object Number: 705373 Size: SH
  71. Remove the front output shaft dust shield.

    72. Object Number: 701637 Size: SH

    Important: Do not scratch the oil seal surface on the front output shaft when removing the retaining ring.

  72. Remove the front output shaft retaining ring.

    73. Object Number: 701643 Size: SH
  73. Remove the front output shaft assembly.

    74. Object Number: 804190 Size: SH
  74. If damaged, remove the speed sensor reluctor wheel from the front output shaft using a hydraulic press. Do not use the speed sensor reluctor wheel again after removal.

    75. Object Number: 164528 Size: SH
  75. Remove the front output shaft bearing retaining ring.

    76. Object Number: 164524 Size: SH
  76. Remove the front output shaft bearing.

    77. Object Number: 165657 Size: SH
  77. Remove the mounting studs, only if they are damaged.

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

    80. Object Number: 801289 Size: SH
  80. Remove the retaining ring for the control actuator lever shaft.

    81. Object Number: 801290 Size: SH
  81. Remove the control actuator lever shaft.
  82. Inspect the control actuator lever bearing and seal for being faulty. Refer to Transfer Case Cleaning and Inspection .
  83. If the bearing is leaking or faulty, remove the bearing from the case.