Transfer Case Assemble

Tools Required

• DT-48021  Seal Installer
• DT-48022  Output Bushing Installer
• J 3289-20  Holding Fixture
• J 8092  Universal Handle
• J 36370  Drive Sprocket Needle Bearing Installer. See Special Tools .
• J 37668-A  Seal Installer. See Special Tools .
• J 42738  Seal Installer
• J 43484  Seal Installer
• J 45380  Transfer Case Rear Bushing Remover and Installer
• J 45383  Input Gear Pilot Bearing Installer. See Special Tools .
• J 45759  Assembly Fixture

Fig 1: View Of Mounting Studs
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.
When installing the new retaining rings in any of the following service procedures, ensure that the retaining rings are properly seated before proceeding to the next service procedure. Always use NEW retaining rings.
1. Install the adapter studs to 29.5-30.5 mm (1.16-1.20 in) in height, if removed.
Fig 2: View Of Front Transfer Case Bench Mount
Courtesy of GENERAL MOTORS CORP.
2. Attach the J 45759  to the front transfer case using the adapter studs. All of the assembly procedures can be performed with the case mounted to the J 45759  .
3. Install the J 45759  (2) into the J 3289-20  (1) and secure with the pivot pin.
Fig 3: Using J 8092 & J 36370 To Install Front Output Shaft Rear Bearing
Courtesy of GENERAL MOTORS CORP.
4. Using the J 8092  (1) and the J 36370  (2), install the front output shaft rear bearing. See Special Tools .
   • The letters on the bearing face toward the tool.
   • Use the double shoulder side of the J 36370  . See Special Tools .
   • The install depth from the case shoulder is 1.4-1.6 mm (0.055-0.063 in).
Fig 4: View Of Rear Output Shaft Bushing & Special Tools
Courtesy of GENERAL MOTORS CORP.
5. SHD only - Install a new rear output shaft bushing, using the J 8092  (1) and DT-48022  (2).
Fig 5: Identifying Control Lever Shaft Support & Seal
Courtesy of GENERAL MOTORS CORP.
NOTE: Refer to Fastener Notice .
6. Install the control lever shaft support and seal.

   Tighten:  Tighten the control lever shaft support to 34 N.m (25 lb ft).

Fig 6: Locating Shift Detent Lever Shaft
Courtesy of GENERAL MOTORS CORP.
7. Install the shift detent lever shaft.
Fig 7: View Of Input Gear Bearing & Inner Retaining Ring
Courtesy of GENERAL MOTORS CORP.
8. For the non-super heavy duty model, install the input gear bearing. The cage on the bearing faces forward.
9. For the non-SHD model, install the input gear bearing inner retaining ring.
10. For the SHD model, install the retaining ring for the input gear bearing.
IMPORTANT: When installing the input gear bearing, ensure that the groove in the input gear bearing is facing up.
11. For the SHD model, expand the retaining ring and install the input gear bearing with the groove up.
12. For the SHD model, fully seat the retaining ring in the bearing groove.
Fig 8: View Of Front Output Shaft Bearing
Courtesy of GENERAL MOTORS CORP.
13. Install the front output shaft front bearing. The cage on the bearing faces forward.
Fig 9: Identifying Front Output Shaft Bearing Retaining Ring
Courtesy of GENERAL MOTORS CORP.
14. Install the front output shaft front bearing inner retaining ring.
Fig 10: View Of Cup Plug
Courtesy of GENERAL MOTORS CORP.
15. If it is a new shaft, or if the cup plug was removed, install the cup plug in the front output shaft, using a suitable driver.

    The installed depth of the cup plug is 26.75 mm (1.05 in) from the end of the shaft.

Fig 11: View Of Front Output Shaft Assembly
Courtesy of GENERAL MOTORS CORP.
16. Install the front output shaft assembly.
Fig 12: Installing Front Output Shaft Retaining Ring
Courtesy of GENERAL MOTORS CORP.
17. Install the front output shaft front bearing outer retaining ring.
Fig 13: View Of First Input Gear Thrust Washer
Courtesy of GENERAL MOTORS CORP.
18. Install the planetary carrier thrust washer. The thrust washer with the tabs must be installed.
Fig 14: Installing Pilot Bearing In The Input Shaft With J 45383
Courtesy of GENERAL MOTORS CORP.
19. Install the needle bearing in the input gear, using the J 8092  (1) and the J 45383  (2). See Special Tools . Use the large diameter of the tool to install the bearing.
Fig 15: View Of Input Gear
Courtesy of GENERAL MOTORS CORP.
20. Install the input gear in the planetary carrier.
21. Ensure the input gear turns freely. If the input gear does not turn freely, inspect for debris.
Fig 16: Identifying Second Input Gear Thrust Washer
Courtesy of GENERAL MOTORS CORP.
22. Install the planetary carrier front thrust washer. The thrust washer without the tabs must be installed.
Fig 17: Locating Input Gear Thrust Plate
Courtesy of GENERAL MOTORS CORP.
IMPORTANT: If the lock plate has a stamped letter "E", ensure that the letter "E" stamped on the lock plate is facing up.
23. Install the planetary carrier lock plate.
Fig 18: View Of Input Gear Retaining Ring
Courtesy of GENERAL MOTORS CORP.
24. Install the retaining ring for the input gear.
Fig 19: View Of Planetary Assembly
Courtesy of GENERAL MOTORS CORP.
25. Install the high/low planetary carrier.
Fig 20: View Of Input Gear Bearing Outer Retaining Ring
Courtesy of GENERAL MOTORS CORP.
26. Install the outer retaining ring for the input gear bearing.
Fig 21: Identifying High/Low Shift Fork On High/Low Range Sleeve
Courtesy of GENERAL MOTORS CORP.
27. Install the high/low shift fork on the high/low range sleeve.
28. Install the high/low range sleeve with the shift fork to the planetary carrier.
29. Position the shift fork pin in the shift detent lever slot.
Fig 22: View Of 2/4 Wheel Drive Synchronizer Gear (2nd Design)
Courtesy of GENERAL MOTORS CORP.
30. Mount the rear output shaft in a soft-jaw vise with the input end up.
31. Install the 2/4 wheel drive synchronizer gear on the rear output shaft.
Fig 23: Exploded View Of Synchronizer Assembly
Courtesy of GENERAL MOTORS CORP.
32. If disassembled, assemble the synchronizer assembly.
    1. Install the inserts (7) in the hub (6).
    2. Install the insert springs (5 and 8).
       • Ensure the hooked end of the spring is located in an insert slot.
       • The hooked ends are opposite each other and not installed in the same insert.
    3. Install the synchronizer sleeve (4) on the synchronizer hub (6). The sleeve with the taper and groove end aligns to the shorter side teeth of the hub.
Fig 24: View Of Synchronizer Assembly Components (2nd Design)
Courtesy of GENERAL MOTORS CORP.
33. Install the synchronizer rings on the rear output shaft. Align the tabs of the outer ring with the slots in the inner ring.
    1. Install the inner ring.
    2. Install the middle ring.
    3. Install the outer ring.
34. Install the synchronizer assembly.
    • The taper or groove end of the synchronizer sleeve faces toward the input end of the rear output shaft.
    • The outer synchronizer ring tabs align to the synchronizer hub.
Fig 25: Identifying Synchronizer Retaining Ring
Courtesy of GENERAL MOTORS CORP.
35. Install the synchronizer retaining ring. Ensure the retaining ring is fully seated in the groove.
Fig 26: View Of 2/4 Wheel Drive Mode Shift Fork
Courtesy of GENERAL MOTORS CORP.
36. Install the 2/4 wheel drive mode shift fork on the synchronizer assembly.
37. Install the shift shaft in the mode shift fork.
Fig 27: View Of Shift Shaft & Synchronizer Assembly With Rear Output Shaft
Courtesy of GENERAL MOTORS CORP.
IMPORTANT: Ensure the mode shift fork is installed with the roller side down.
38. Install the shift shaft and the synchronizer assembly with the rear output shaft in the front case half and the high/low range sleeve.
Fig 28: Identifying Drive Chains & Sprockets
Courtesy of GENERAL MOTORS CORP.
IMPORTANT: When performing the following service procedure, ensure that marks that were used to mark the position of the chain to the relationship of the chain to the sprockets.
39. Install the drive chain on the front output shaft and the rear output shaft assembly.
Fig 29: View Of Drive Sprocket Retaining Ring
Courtesy of GENERAL MOTORS CORP.
40. Install the drive sprocket retaining ring.
Fig 30: Locating Driven Sprocket Retaining Ring
Courtesy of GENERAL MOTORS CORP.
41. Install the driven sprocket retaining ring.
Fig 31: Oil Pump Assembly
Courtesy of GENERAL MOTORS CORP.
42. Install the oil pump on the rear output shaft.
Fig 32: Identifying Oil Pump Suction Pipe O-Ring
Courtesy of GENERAL MOTORS CORP.
43. Install a new oil pump O-ring for the oil pump suction pipe in the oil pump.
Fig 33: Identifying Rear Output Shaft Speed Sensor Reluctor Wheel
Courtesy of GENERAL MOTORS CORP.
IMPORTANT: Install the speed reluctor wheel with the step toward the oil pump assembly.
44. Install the speed reluctor wheel.
Fig 34: View Of Rear Output Shaft Bearing
Courtesy of GENERAL MOTORS CORP.
IMPORTANT: When installing the rear output shaft bearing on the rear output shaft, ensure the groove on the rear output shaft bearing is facing up.
45. Install the rear output shaft bearing.
Fig 35: Locating Rear Output Shaft Bearing Retaining Ring
Courtesy of GENERAL MOTORS CORP.
46. Install a NEW rear output shaft bearing retaining ring.
Fig 36: Expanded View Of Shift Detent Plunger
Courtesy of GENERAL MOTORS CORP.
47. Install a new O-ring seal on the shift detent spring bolt.
48. Install the shift detent spring, the plunger, and the bolt.

    Tighten:  Tighten the shift detent bolt to 17 N.m (13 lb ft).

Fig 37: Locating Oil Pump Suction Pipe Assembly
Courtesy of GENERAL MOTORS CORP.
49. Install the oil pump suction pipe assembly.
    1. Install the screen in the case.
    2. Install the suction pipe to the oil pump.
    3. Inspect for the O-ring not being damaged and in the proper position.
Fig 38: Locating Magnet
Courtesy of GENERAL MOTORS CORP.
50. Install the magnet.
Fig 39: Locating Shift Fork Shaft Spring
Courtesy of GENERAL MOTORS CORP.
51. Install the shift fork shaft spring on the shift shaft.
Fig 40: View Of Oil Pump Wear Sleeve
Courtesy of GENERAL MOTORS CORP.
52. Remove the 1st design oil pump wear sleeve from the rear case half.
Fig 41: Identifying 2nd Design Oil Pump Wear Sleeve
Courtesy of GENERAL MOTORS CORP.
IMPORTANT: Ensure the oil pump wear sleeve is properly positioned to the largest lug of the oil pump.
53. Install the 2nd design oil pump wear sleeve (1) to the oil pump (2).
Fig 42: Identifying Locating Pins
Courtesy of GENERAL MOTORS CORP.
IMPORTANT: Ensure the locating pins are installed in the front case half.
54. Install the locating pins in the front case, if necessary.
Fig 43: Applying Sealant To Front Case Sealing Surface
Courtesy of GENERAL MOTORS CORP.
NOTE: Apply the proper amount of sealant to the flange when assembling the transfer case. Excessive amounts of sealant can plug the oil pump screen, resulting in internal component failure.
IMPORTANT: Ensure both sealing surfaces of the front and rear case halves are free of dirt, oil, and cleaning solvent.
55. Apply a 2 mm (0.078 in) bead of RTV sealant GM P/N 12345739 (Canadian P/N 10953541) or equivalent to the front case half.
Fig 44: Front Case & Rear Case Half Assembly
Courtesy of GENERAL MOTORS CORP.
56. Align the outer retaining ring tabs for the rear output shaft bearing with the slot in the rear case half.
57. Install the rear case half to the front case half.
Fig 45: Positioning Snap Ring Pliers In Access Opening
Courtesy of GENERAL MOTORS CORP.
58. Using a pair of snap ring pliers, open the outer retaining ring for the rear output shaft bearing.
59. Insert a rubber coated screwdriver into the speed sensor hole and lift up on the speed reluctor wheel, then seat the retaining ring.
Fig 46: View Of Transfer Case Bolts/Studs With The Cup Style Aluminum Washer
Courtesy of GENERAL MOTORS CORP.
NOTE: This component is made of magnesium. Proper assembly is required to prevent damage. Ensure the magnesium transfer case housings are properly insulated from all external steel components, or galvanic corrosion will occur. Use only the transfer case bolts/studs with the cup style aluminum washer. Use only aluminum fill and drain plugs. Use only aluminum brackets under the case bolts. Ensure new seals are installed that have a rubber insulated outside diameter and have no tears or cuts. Extensive damage will occur if there is galvanic corrosion between the magnesium and steel components.
60. Align the brackets to the proper bolt holes.
61. Install the NEW case half bolts or studs and the aluminum washers.

    Tighten:  Tighten the case half bolts to 38 N.m (28 lb ft).

Fig 47: View Of Rear Output Shaft Bushing
Courtesy of GENERAL MOTORS CORP.
IMPORTANT: The J 45380  does not work on the SHD version of the transfer case.
62. LD and HD only - Install a new rear output shaft bushing, using the J 45380  .
    1. Install the bushing on the finger section of the J 45380  .
    2. Install the finger section to the main body of the J 45380  .
    3. Position the bushing and tool to the case.
    4. Using a hammer and the J 45380  , install the bushing.
Fig 48: View Of Output Shaft Seal
Courtesy of GENERAL MOTORS CORP.
IMPORTANT: When installing the rear output shaft seal, ensure that the drain hole is pointed down at an angle at which the transfer case would be installed in the vehicle.
63. LD and HD only - Using the J 37668-A  , install the rear output shaft seal to the transfer case. See Special Tools .
Fig 49: View Of Rear Output Shaft Seal & Special Tools
Courtesy of GENERAL MOTORS CORP.
IMPORTANT: When installing the rear output shaft seal, ensure that the drain hole is pointed down at an angle at which the transfer case would be installed in the vehicle.
64. SHD only - Using the J 8092  (1) and DT-48021  (2), install the rear output shaft seal to the transfer case.
Fig 50: J 8092 & J 43484
Courtesy of GENERAL MOTORS CORP.
65. Using the J 43484  (2) and the J 8092  (1), install the front output shaft seal in the transfer case.
Fig 51: View Of Transfer Case Input Shaft Seal
Courtesy of GENERAL MOTORS CORP.
66. Using the J 42738  , install the input shaft seal to the transfer case.
Fig 52: Locating Transfer Case Speed Sensor
Courtesy of GENERAL MOTORS CORP.
67. Install a NEW O-ring seal on the vehicle speed sensor.
68. Lubricate the vehicle speed sensor O-ring seal with transfer case fluid.
69. Install the speed sensor in the transfer case.

    Tighten:  Tighten the speed sensor to 15 N.m (11 lb ft).

Fig 53: Identifying New Aluminum Vent Pipe
Courtesy of GENERAL MOTORS CORP.
70. Apply a thin layer of retaining compound GM P/N 12377901, Canadian P/N 10953504, or equivalent, to the NEW aluminum vent pipe.
71. Tap the NEW aluminum vent pipe into the case; ensure the vent pipe is aligned in the direction shown.
Fig 54: Locating Gear Indicator Switch
Courtesy of GENERAL MOTORS CORP.
72. Install the gear indicator switch with the gasket.

    Tighten:  Tighten the gear indicator switch to 27 N.m (20 lb ft).

Fig 55: View Of Shift Control Lever Retaining Bolt
Courtesy of GENERAL MOTORS CORP.
73. Install the shift control lever and foam seal.
74. Install the shift control lever retaining bolt.

    Tighten:  Tighten the shift control lever retaining bolt to 27 N.m (20 lb ft).

Fig 56: Locating Transfer Case Access Plug
Courtesy of GENERAL MOTORS CORP.
IMPORTANT: Ensure that the correct access hole plug is used for the SHD models.
75. Install the access hole plug in the transfer case.
Fig 57: View Of Fill & Drain Plugs
Courtesy of GENERAL MOTORS CORP.
IMPORTANT: Use only drain and fill plugs made of aluminum. Steel or brass plugs are not compatible with the magnesium case.
76. Install the drain plug (2).

    Tighten:  Tighten the drain plug to 20 N.m (15 lb ft).

77. Install the fill plug (1).

    Tighten:  Tighten the fill plug to 20 N.m (15 lb ft).