Transfer Case Assemble

Tools Required

• J 3289-20  Holding Fixture
• J 8092  Universal Driver Handle
• J 36370  Drive Sprocket Needle Bearing Installer
• J 37668-A  Output Shaft Seal Installer
• J 42737  Sector Bearing Installer. See Special Tools .
• J 42738  Seal Installer
• J 43484  Front Output Shaft Seal Installer
• J 45380  Transfer Case Rear Bushing Remover and Installer
• J 45383  Input Gear Pilot Bearing Installer
• J 45759  Assembly Fixture

IMPORTANT: The following service procedure covers heavy duty 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.
Fig 1: Installing Mounting Studs
Courtesy of GENERAL MOTORS CORP.
1. Install the adapter studs to 29.5-30.5 mm (1.16-1.20 in) in height, if removed.
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 2: View Of Front Transfer Case Bench Mount

   Courtesy of GENERAL MOTORS CORP.
4. Using the J 8092  (1) and the J 36370  (2), install the front output shaft rear bearing.
   Fig 3: Installing Front Output Shaft Rear Bearing

   Courtesy of GENERAL MOTORS CORP.
   • The letters on the bearing face toward the tool.
   • Use the double shoulder side of the J 36370  .
   • The install depth from the case shoulder is 1.4-1.6 mm (0.055-0.063 in).
5. Using the J 42737  , install the shift detent lever shaft bearing. See Special Tools . The seal side of the bearing faces outward.
   Fig 4: Installing J 42737

   Courtesy of GENERAL MOTORS CORP.
6. Install the shift detent lever shaft.
   Fig 5: Installing Shift Detent Lever Shaft

   Courtesy of GENERAL MOTORS CORP.
7. Install the shift detent lever shaft retaining ring.
   Fig 6: Installing Shift Detent Lever Shaft Retaining Ring

   Courtesy of GENERAL MOTORS CORP.
8. For the non SHD model, install the input gear bearing. The cage side of the bearing faces forward.
   Fig 7: Installing Input Gear Bearing & Inner Retaining Ring

   Courtesy of GENERAL MOTORS CORP.
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 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.
13. Install the front output shaft front bearing. The cage side of the bearing faces forward.
    Fig 8: Installing Front Output Shaft Bearing

    Courtesy of GENERAL MOTORS CORP.
14. Install the front output shaft front bearing inner retaining ring.
    Fig 9: Identifying Front Output Shaft Bearing Retaining Ring

    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 10: Installing Cup Plug

    Courtesy of GENERAL MOTORS CORP.
16. Install the front output shaft assembly.
    Fig 11: Installing Front Output Shaft Assembly

    Courtesy of GENERAL MOTORS CORP.
17. Install the front output shaft front bearing outer retaining ring.
    Fig 12: Installing Front Output Shaft Retaining Ring

    Courtesy of GENERAL MOTORS CORP.
18. Install the planetary carrier thrust washer.
    Fig 13: Installing First Input Gear Thrust Washer

    Courtesy of GENERAL MOTORS CORP.

    The thrust washer with the tabs must be installed.

19. Install the needle bearing in the input gear, using the J 8092  (1) and the J 45383  (2). Use the large diameter of the tool to install the bearing.
    Fig 14: Installing Pilot Bearing In The Input Shaft With J 45383

    Courtesy of GENERAL MOTORS CORP.
20. Install the input gear in the planetary carrier.
    Fig 15: Installing Input Gear

    Courtesy of GENERAL MOTORS CORP.
21. Ensure the input gear turns freely. If the input gear does not turn freely, inspect for debris.
22. Install the planetary carrier front thrust washer.
    Fig 16: Installing Planetary Carrier Front Thrust Washer

    Courtesy of GENERAL MOTORS CORP.

    The thrust washer without the tabs must be installed.

IMPORTANT: If the lock plate has a stamped letter "E", ensure that the letter "E" stamped on the lock plate is facing up.
Fig 17: Installing Planetary Carrier Lock Plate
Courtesy of GENERAL MOTORS CORP.
23. Install the planetary carrier lock plate.
24. Install the retaining ring for the input gear.
    Fig 18: Installing Input Gear Retaining Ring

    Courtesy of GENERAL MOTORS CORP.
25. Install the high/low planetary carrier.
    Fig 19: Installing Planetary Assembly

    Courtesy of GENERAL MOTORS CORP.
26. Install the outer retaining ring for the input gear bearing.
    Fig 20: Installing Input Gear Bearing Retaining Ring

    Courtesy of GENERAL MOTORS CORP.
27. Assemble the high/low shift fork assembly.
    Fig 21: Assembling High/Low Shift Fork Assembly

    Courtesy of GENERAL MOTORS CORP.
28. Install the shift fork pads.
29. Install the high/low shift fork on the high/low range sleeve.
    Fig 22: Installing Shift Fork On High/Low Range Sleeve

    Courtesy of GENERAL MOTORS CORP.
30. Install the high/low range sleeve with the shift fork to the planetary carrier.
    Fig 23: Installing High/Low Range Sleeve With Shift Fork

    Courtesy of GENERAL MOTORS CORP.
31. Position the shift fork pin in the shift detent lever slot.
32. Mount the rear output shaft in a soft-jaw vise with the input end up.
33. Install the 2/4 wheel drive synchronizer gear on the rear output shaft.
    Fig 24: Installing 2/4 Wheel Drive Synchronizer Gear

    Courtesy of GENERAL MOTORS CORP.
34. If disassembled, assemble the synchronizer assembly.
    Fig 25: Exploded View Of Synchronizer Assembly

    Courtesy of GENERAL MOTORS CORP.
    1. Install the inserts (7) in the hub (6).
    2. Install the insert springs (5 and 8).
       • The hooked ends are opposite each other and not installed in the same insert.
       • Ensure the hooked end of the spring is located in an insert slot.
    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.
35. Install the synchronizer rings on the rear output shaft. Align the tabs of the outer ring with the slots in the inner ring.
    Fig 26: Assembling Synchronizer Rings On Rear Output Shaft

    Courtesy of GENERAL MOTORS CORP.
    1. Install the inner ring.
    2. Install the middle ring.
    3. Install the outer ring.
36. 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.
37. Install the synchronizer retaining ring. Ensure the retaining ring is fully seated in the groove.
    Fig 27: Installing Synchronizer Retaining Ring

    Courtesy of GENERAL MOTORS CORP.
38. Install the 2/4 wheel drive mode shift fork on the synchronizer assembly.
    Fig 28: Installing 2/4 Wheel Drive Mode Shift Fork

    Courtesy of GENERAL MOTORS CORP.
39. Install the shift shaft in the mode shift fork.
IMPORTANT: Ensure the mode shift fork is installed with the roller side down.
Fig 29: Installing Shift Shaft & Synchronizer Assembly
Courtesy of GENERAL MOTORS CORP.
40. Install the shift shaft and the synchronizer assembly, with the rear output shaft, in the front case half and the high/low range sleeve.
IMPORTANT: When performing the following service procedure, align the marks of the drive chain and sprockets, if using the chain and sprockets again.
Fig 30: Identifying Drive Chains & Sprockets
Courtesy of GENERAL MOTORS CORP.
41. Install the drive chain on the front output shaft and the rear output shaft assembly.
42. Install the drive sprocket retaining ring.
    Fig 31: Installing Drive Sprocket Retaining Ring

    Courtesy of GENERAL MOTORS CORP.
43. Install the driven sprocket retaining ring.
    Fig 32: Installing Driven Sprocket Retaining Ring

    Courtesy of GENERAL MOTORS CORP.
44. Install a new oil pump O-ring, for the oil pump suction pipe, in the oil pump.
    Fig 33: Installing Oil Pump Suction Pipe O-Ring

    Courtesy of GENERAL MOTORS CORP.
45. Install the oil pump on the rear output shaft.
    Fig 34: Installing Oil Pump Assembly

    Courtesy of GENERAL MOTORS CORP.
IMPORTANT: Install the speed reluctor wheel with the step toward the oil pump assembly.
Fig 35: Installing Speed Sensor Reluctor Wheel
Courtesy of GENERAL MOTORS CORP.
46. Install the speed reluctor wheel.
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.
Fig 36: Installing Rear Output Shaft Bearing
Courtesy of GENERAL MOTORS CORP.
47. Install the rear output shaft bearing.
48. Install a NEW rear output shaft bearing retaining ring.
    Fig 37: Installing Rear Output Shaft Bearing Retaining Ring

    Courtesy of GENERAL MOTORS CORP.
49. Install a new O-ring seal on the shift detent spring bolt.
NOTE: Refer to Fastener Notice .
Fig 38: Installing Shift Detent Plunger
Courtesy of GENERAL MOTORS CORP.
50. Install the shift detent spring, the plunger, and the bolt.

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

51. Install the oil pump suction pipe assembly.
    Fig 39: Installing Oil Pump Suction Pipe Assembly

    Courtesy of GENERAL MOTORS CORP.
    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.
52. Install the magnet.
    Fig 40: Installing Magnet

    Courtesy of GENERAL MOTORS CORP.
53. Install the shift fork shaft spring on the shift shaft.
    Fig 41: Installing Shift Fork Shaft Spring

    Courtesy of GENERAL MOTORS CORP.
IMPORTANT: Ensure that the oil pump wear sleeve is in the correct position.
Fig 42: Installing Oil Pump Wear Sleeve
Courtesy of GENERAL MOTORS CORP.
54. Install the oil pump wear sleeve, if removed.
IMPORTANT: Ensure the locating pins are installed in the front case half.
Fig 43: Installing Locating Pins
Courtesy of GENERAL MOTORS CORP.
55. Install the locating pins in the front case, if necessary.
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.
Fig 44: Applying Sealant To Front Case Sealing Surface
Courtesy of GENERAL MOTORS CORP.
56. 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.
57. Align the outer retaining ring tabs for the rear output shaft bearing with the slot in the rear case half.
58. Install the rear case half to the front case half.
    Fig 45: Assembling Front & Rear Case Halves

    Courtesy of GENERAL MOTORS CORP.
59. Using snap ring pliers, open the outer retaining ring for the rear output shaft bearing.
    Fig 46: Opening Outer Retaining Ring For Rear Output Shaft Bearing

    Courtesy of GENERAL MOTORS CORP.
60. Insert a rubber coated screwdriver into the speed sensor hole.
61. Lift up on the speed reluctor wheel then seat the retaining ring.
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.
62. Align the brackets to the proper bolt holes.
63. Install the NEW case half bolts or studs and the aluminum washers.
    Fig 47: Installing Transfer Case Bolts/Studs

    Courtesy of GENERAL MOTORS CORP.

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

IMPORTANT: The J 45380  does not work on the SHD version of the transfer case.
Fig 48: Installing Rear Output Shaft Bushing
Courtesy of GENERAL MOTORS CORP.
64. 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.
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.
Fig 49: Installing Output Shaft Seal
Courtesy of GENERAL MOTORS CORP.
65. Using the J 37668-A  , install the rear output shaft seal to the transfer case.
66. Using the J 43484  (2) and the J 8092  (1), install the front output shaft seal in the transfer case.
    Fig 50: Installing Front Output Shaft Seal Using J 8092 & J 43484

    Courtesy of GENERAL MOTORS CORP.
67. Using the J 42738  , install the input shaft seal to the transfer case.
    Fig 51: Installing Transfer Case Input Shaft Seal

    Courtesy of GENERAL MOTORS CORP.
68. Install a NEW O-ring seal on the vehicle speed sensor.
    Fig 52: Installing Vehicle Speed Sensor

    Courtesy of GENERAL MOTORS CORP.
69. Lubricate the vehicle speed sensor O-ring seal with transfer case fluid.
70. Install the speed sensor in the transfer case.

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

IMPORTANT: A new actuator encoder motor does not come with locating pins. Locating pins must be installed in the encoder motor for proper operation.
71. Install the locating pins in the actuator encoder motor.
72. Install the actuator insulator gasket on the encoder motor.
73. Install the actuator encoder motor to the transfer case. Rotate the control actuator lever shaft to align to the encoder motor.
74. Install the mounting bolts for the actuator encoder motor.

    Tighten:  Tighten the actuator encoder motor mounting bolts, in the sequence shown, to 20 N.m (15 lb ft).

    Fig 53: Installing Encoder Motor Bolts

    Courtesy of GENERAL MOTORS CORP.
75. Install the wiring harness to the bracket.
76. Install the vent tube elbow, if damaged.
    Fig 54: Installing Vent Tube Elbow

    Courtesy of GENERAL MOTORS CORP.
IMPORTANT: Ensure that the correct access hole plug is used for the SHD model.
Fig 55: Installing Transfer Case Access Plug
Courtesy of GENERAL MOTORS CORP.
77. Install the access hole plug in the transfer case.
IMPORTANT: Use only drain and fill plugs made of aluminum. Steel or brass plugs are not compatible with the magnesium case.
Fig 56: Installing Fill & Drain Plugs
Courtesy of GENERAL MOTORS CORP.
78. Install the drain plug (2).

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

79. Install the fill plug (1).

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