Transfer Case Disassemble

Tools Required

• J 3289-20  Holding Fixture
• 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

IMPORTANT:
• The following service procedure covers light duty, heavy duty 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.
Fig 1: Identifying J 45759
Courtesy of GENERAL MOTORS CORP.
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. 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.
   Fig 2: View Of Front Transfer Case Bench Mount

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4. Remove the drain plug (2) and the fill plug (1).
   Fig 3: Locating Fill & Drain Plugs

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5. Drain the fluid from the transfer case.
6. Remove the rear output shaft seal.
   Fig 4: Removing Rear Output Shaft Seal

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7. Inspect the rear output shaft bushing for scoring or wear.
IMPORTANT: The J 45380  does not work on the SHD version of the transfer case.
Fig 5: Removing Rear Output Shaft Bushing
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8. Remove the rear output shaft bushing using the J 45380  .
   • 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.
9. Remove the access hole plug.
   Fig 6: Locating Transfer Case Access Plug

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10. Remove the transfer case vehicle speed sensor.
    Fig 7: Removing Transfer Case Speed Sensor

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11. Remove the gear indicator switch and gasket.
    Fig 8: Removing Gear Indicator Switch

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12. Remove the vent tube, ONLY if the vent tube elbow is damaged.
    Fig 9: Removing Vent Tube Elbow

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13. Remove the shift control lever bolt.
    Fig 10: Removing Shift Control Lever Bolt

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14. Remove the shift control lever and foam seal.
IMPORTANT: The magnesium transfer cases use new style bolts that have a cup style washer. The cup washer is only available with the bolt. If the cup washer is not damaged, the bolt can be used again.
Fig 11: Removing Transfer Case Bolts/Studs
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15. Remove the transfer case retaining bolts or studs, the washers, and the brackets.
16. Mark the location of the brackets and studs for correct assembly.
17. Insert a screwdriver into the slot on the left side of the transfer case.
    Fig 12: Locating Slot On Left Side Of Transfer Case

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18. Insert a screwdriver into the slot on the right side of the transfer case.
    Fig 13: Locating Slot On Right Side On Transfer Case

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19. With equal pressure applied on each screwdriver, separate the front half and the rear half.
20. Using a pair of snap ring pliers, release the outside retaining ring for the rear output shaft bearing.
    Fig 14: Using Snap Ring Pliers To Release Outside Retaining Ring

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21. Remove the rear case half from the front case half.
    Fig 15: Removing Rear Case Half

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22. Remove the rear output shaft bearing retaining ring.
    Fig 16: Removing Rear Output Shaft Bearing Retaining Ring

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23. Remove the rear output shaft bearing.
    Fig 17: Removing Rear Output Shaft Bearing

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24. Remove the speed reluctor wheel.
    Fig 18: Removing Speed Sensor Reluctor Wheel

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25. Remove the oil pump suction pipe assembly. Do not remove the screen from the pipe.
    Fig 19: Removing Oil Pump Suction Pipe Assembly

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26. Remove the magnet.
    Fig 20: Locating Magnet

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27. Remove the oil pump assembly.
    Fig 21: Removing Oil Pump Assembly

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28. Remove the O-ring seal for the oil pump suction pipe.
    Fig 22: Removing Oil Pump Suction Pipe O-Ring

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29. Remove the shift fork shaft spring.
    Fig 23: Removing Shift Fork Shaft Spring

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30. Remove the driven sprocket retaining ring.
    Fig 24: Removing Driven Sprocket Retaining Ring

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31. Remove the drive sprocket retaining ring.
    Fig 25: Removing Drive Sprocket Retaining Ring

    Courtesy of GENERAL MOTORS CORP.
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.
Fig 26: Removing Drive Chains & Sprockets
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32. Remove the drive chain and the sprockets from the mainshaft and the front output shaft.
IMPORTANT: Remove the rear output shaft as an assembly with the synchronizer and the shift fork.
Fig 27: Removing Rear Output Shaft Assembly
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33. Remove the rear output shaft with the shift fork. The shift shaft can remain in the case.
34. Remove the 2/4 wheel drive mode shift fork from the synchronizer assembly.
35. Mount the rear output shaft in a soft-jaw vise with the input end up.
36. Remove the synchronizer assembly retaining ring.
    Fig 28: Removing Synchronizer Retaining Ring

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37. Remove the synchronizer as an assembly.
38. Remove the synchronizer outer ring, middle ring, and inner ring.
    Fig 29: Removing Synchronizer Components

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39. Remove the 2/4 wheel drive synchronizer gear from the rear output shaft.
    Fig 30: Removing 2/4 Wheel Drive Synchronizer Gear

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40. If necessary, disassemble the synchronizer assembly.
    Fig 31: Exploded View Of Synchronizer Assembly

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    • 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).
41. Remove the shift detent spring bolt and O-ring seal.
42. Remove the shift detent spring and the plunger.
    Fig 32: Removing Shift Detent Plunger

    Courtesy of GENERAL MOTORS CORP.
43. Remove the shift shaft from the high/low range fork and the front case.
    Fig 33: Removing Shift Shaft

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44. Remove the high/low range sleeve and the shift fork.
    Fig 34: Removing Shift Fork From High/Low Range Sleeve

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45. Remove the range sleeve from the shift fork.
46. Remove the input shaft seal.
    Fig 35: Removing Input Shaft Seal

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47. Remove the outer retaining ring for the input gear bearing.
    Fig 36: Removing Input Shaft Retaining Ring

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48. Remove the high/low planetary carrier.
    Fig 37: Removing High/Low Planetary Carrier

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49. Remove the retaining ring for the input gear.
    Fig 38: Removing Input Gear Retaining Ring

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50. Remove the planetary carrier lock plate.
    Fig 39: Removing Input Gear Thrust Plate

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51. Remove the planetary carrier front thrust washer.
    Fig 40: Removing Second Input Gear Thrust Washer

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52. Remove the input gear.
    Fig 41: Removing Input Gear

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53. Remove the planetary carrier rear thrust washers.
    Fig 42: Removing Planetary Carrier Thrust Washer

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54. Inspect the needle bearing in the input gear for being faulty. Refer to Cleaning and Inspection .
55. Remove the needle bearing from the input gear using a brass drift and a hammer, if faulty.
    Fig 43: Removing Needle Bearing From Input Gear

    Courtesy of GENERAL MOTORS CORP.
IMPORTANT: For the super heavy duty version of the NVG 261, 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 261, 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.
Fig 44: Removing Input Gear Bearing & Retaining Ring
Courtesy of GENERAL MOTORS CORP.
56. Remove the input gear bearing retaining ring.
57. Remove input gear bearing.
58. Remove the inner retaining ring for the front output shaft bearing.
    Fig 45: Removing Front Output Shaft Bearing Inner Retaining Ring

    Courtesy of GENERAL MOTORS CORP.
59. Using a soft-face hammer, remove the front output shaft, with the bearing, from the front case half.
    Fig 46: Removing Front Output Shaft With Bearing

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60. Using a suitable punch, remove the front output shaft seal from the front case half.
    Fig 47: Locating Front Output Shaft Seal

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61. Remove the outer retaining ring for the front output shaft bearing.
    Fig 48: Removing Outer Retaining Ring For Front Output Shaft Bearing

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62. Inspect the front output shaft bearing for being faulty. Refer to Cleaning and Inspection .
63. Remove the bearing from the front output shaft. Do not use the bearing again after removal.
    Fig 49: Removing Front Output Shaft Bearing

    Courtesy of GENERAL MOTORS CORP.
64. If the cup plug in the front output shaft is leaking, remove the plug using a brass drift.
    Fig 50: Removing Cup Plug

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65. Inspect the front output shaft rear bearing for being faulty. Refer to Cleaning and Inspection .
66. If the bearing is faulty, remove the bearing using the J 23907  (2) and the J 26941  (1).
    Fig 51: Removing Front Output Shaft Rear Bearing With J 23907 & J 26941

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67. Remove the shift detent lever shaft.
    Fig 52: Locating Shift Detent Lever Shaft

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68. Inspect the bearing and seal in the shift control lever shaft support for being faulty. Refer to Cleaning and Inspection .
69. If the seal or bearing is faulty, remove the shift control lever shaft support and the support washer.
    Fig 53: Removing Control Lever Shaft Support And Seal

    Courtesy of GENERAL MOTORS CORP.