Transfer Case Disassemble

Tools Required

• DT-48209  Bushing Remover
• J 3289-20  Holding Fixture
• J 8092  Driver Handle
• J 23907  Slide Hammer with Bearing Adapter. See Special Tools .
• J 26941  Bushing and Bearing Remover - 3-4 inch
• J 45380  Transfer Case Rear Bushing Remover and Installer
• J 45759  Assembly Fixture

Fig 1: Identifying J 45759
Courtesy of GENERAL MOTORS CORP.
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  .
Fig 2: View Of Front Transfer Case Bench Mount
Courtesy of GENERAL MOTORS CORP.
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 3: View Of Fill & Drain Plugs
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4. Remove the drain plug (2) and the fill plug (1).
5. Drain the fluid from the transfer case.
Fig 4: View Of Rear Output Shaft Seal
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6. Remove the rear output shaft seal.
Fig 5: View Of Rear Output Shaft Bushing
Courtesy of GENERAL MOTORS CORP.
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. Review step 67 if removal of the SHD rear output shaft bushing is required.
8. LD and HD only - 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.
Fig 6: Locating Transfer Case Access Plug
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9. Remove the access hole plug.
Fig 7: Locating Transfer Case Speed Sensor
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10. Remove the transfer case vehicle speed sensor.
Fig 8: View Of Gear Indicator Switch
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11. Remove the gear indicator switch and gasket.
Fig 9: Identifying Vent Tube Elbow
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12. Remove the plastic vent from the case; a NEW aluminum vent must be installed during assembly.
Fig 10: Locating Shift Control Lever Bolt
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13. Remove the shift control lever bolt.
14. Remove the shift control lever and foam seal.
Fig 11: View Of Transfer Case Bolts/Studs With The Cup Style Aluminum Washer
Courtesy of GENERAL MOTORS CORP.
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.
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.
Fig 12: Identifying Slot On Right Side Of Transfer Case
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17. Insert a screwdriver into the slot on the left side of the transfer case.
Fig 13: Locating Slot On Right Side On Transfer Case
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18. Insert a screwdriver into the slot on the right side of the transfer case.
19. With equal pressure applied on each screwdriver, separate the front half and the rear half.
Fig 14: Positioning Snap Ring Pliers In Access Opening
Courtesy of GENERAL MOTORS CORP.
20. Using a pair of snap ring pliers, release the outside retaining ring for the rear output shaft bearing.
Fig 15: Front Case & Rear Case Half Assembly
Courtesy of GENERAL MOTORS CORP.
21. Remove the rear case half from the front case half.
Fig 16: Locating Rear Output Shaft Bearing Retaining Ring
Courtesy of GENERAL MOTORS CORP.
22. Remove the rear output shaft bearing retaining ring.
Fig 17: View Of Rear Output Shaft Bearing
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23. Remove the rear output shaft bearing.
Fig 18: Identifying Rear Output Shaft Speed Sensor Reluctor Wheel
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24. Remove the speed reluctor wheel.
Fig 19: Locating Oil Pump Suction Pipe Assembly
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25. Remove the oil pump suction pipe assembly. Do not remove the screen from the pipe.
Fig 20: Locating Magnet
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26. Remove the magnet.
Fig 21: Oil Pump Assembly
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27. Remove the oil pump assembly.
Fig 22: Identifying Oil Pump Suction Pipe O-Ring
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28. Remove the O-ring seal for the oil pump suction pipe.
Fig 23: Locating Shift Fork Shaft Spring
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29. Remove the shift fork shaft spring.
Fig 24: Locating Driven Sprocket Retaining Ring
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30. Remove the driven sprocket retaining ring.
Fig 25: View Of Drive Sprocket Retaining Ring
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31. Remove the drive sprocket retaining ring.
Fig 26: Identifying Drive Chains & Sprockets
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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.
32. Remove the drive chain and the sprockets from the mainshaft and the front output shaft.
Fig 27: View Of Rear Output Shaft Assembly
Courtesy of GENERAL MOTORS CORP.
IMPORTANT: Remove the rear output shaft as an assembly with the synchronizer and the shift fork.
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.
Fig 28: Identifying Synchronizer Retaining Ring
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35. Mount the rear output shaft in a soft-jaw vise with the input end up.
36. Remove the synchronizer assembly retaining ring.
Fig 29: View Of Synchronizer Assembly Components (2nd Design)
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37. Remove the synchronizer as an assembly.
38. Remove the synchronizer outer ring, middle ring, and inner ring.
Fig 30: View Of 2/4 Wheel Drive Synchronizer Gear (2nd Design)
Courtesy of GENERAL MOTORS CORP.
39. Remove the 2/4 wheel drive synchronizer gear from the rear output shaft.
Fig 31: Exploded View Of Synchronizer Assembly
Courtesy of GENERAL MOTORS CORP.
40. If necessary, disassemble the synchronizer assembly.
    • 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).
Fig 32: Expanded View Of Shift Detent Plunger
Courtesy of GENERAL MOTORS CORP.
41. Remove the shift detent spring bolt and O-ring seal.
42. Remove the shift detent spring and the plunger.
Fig 33: View Of Shift Shaft
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43. Remove the shift shaft from the high/low range fork and the front case.
Fig 34: Identifying High/Low Shift Fork On High/Low Range Sleeve
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44. Remove the high/low range sleeve and the shift fork.
45. Remove the range sleeve from the shift fork.
Fig 35: Locating Input Shaft Seal
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46. Remove the input shaft seal.
Fig 36: Identifying Input Shaft Retaining Ring
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47. Remove the outer retaining ring for the input gear bearing.
Fig 37: View Of High/Low Planetary Carrier
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48. Remove the high/low planetary carrier.
Fig 38: View Of Input Gear Retaining Ring
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49. Remove the retaining ring for the input gear.
Fig 39: Locating Input Gear Thrust Plate
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50. Remove the planetary carrier lock plate.
Fig 40: Identifying Second Input Gear Thrust Washer
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51. Remove the planetary carrier front thrust washer.
Fig 41: View Of Input Gear
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52. Remove the input gear.
Fig 42: View Of First Input Gear Thrust Washer
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53. Remove the planetary carrier rear thrust washers.
Fig 43: Removing Pilot Bearing From Input Gear
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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 44: View Of Input Gear Bearing & Inner Retaining Ring
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.
56. Remove the input gear bearing retaining ring.
57. Remove input gear bearing.
Fig 45: Locating Front Output Shaft Bearing Inner Retaining Ring
Courtesy of GENERAL MOTORS CORP.
58. Remove the inner retaining ring for the front output shaft bearing.
Fig 46: View Of Front Output Shaft With Bearing
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59. Using a soft-face hammer, remove the front output shaft, with the bearing, from the front case half.
Fig 47: Locating Front Output Shaft Seal
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60. Using a suitable punch, remove the front output shaft seal from the front case half.
Fig 48: Identifying Front Output Shaft Bearing Outer Retaining Ring
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61. Remove the outer retaining ring for the front output shaft bearing.
Fig 49: View Of 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 50: View Of Cup Plug
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 51: Removing Front Output Shaft Rear Bearing With J 23907 & J 26941
Courtesy of GENERAL MOTORS CORP.
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). See Special Tools .
Fig 52: View Of Rear Output Shaft Bushing & Special Tools
Courtesy of GENERAL MOTORS CORP.
67. SHD only - Remove the rear output shaft bushing using the J 8092  (1) and DT-48209  (2).
Fig 53: Locating Shift Detent Lever Shaft
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68. Remove the shift detent lever shaft.
Fig 54: Identifying Control Lever Shaft Support & Seal
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69. Inspect the bearing and seal in the shift control lever shaft support for being faulty. Refer to Cleaning and Inspection .
70. If the seal or bearing is faulty, remove the shift control lever shaft support and the support washer.