Transfer Case Assemble

Tools Required

• J 3289-20  Holding Fixture. See Special Tools .
• J 8092  Universal Driver Handle
• J 22912-01  Split Plate Bearing Puller
• J 36850  Transjel Lubricant. See Special Tools .
• J 42176  Universal Driver Handle - Non-Threaded. See Special Tools .
• J 42738  Seal Installer. See Special Tools .
• J 43484  Front Output Shaft Seal Installer. See Special Tools .
• J 45756  Rear Output Shaft Seal Installer. See Special Tools .
• J 45757  Mainshaft Support Bushing and Bearing Installer. See Special Tools .
• J 45759  Assembly Fixture. See Special Tools .

Fig 1: Installing Transfer Case Mounting Studs (If Removed)
Courtesy of GENERAL MOTORS CORP.
NOTE: Refer to Fastener Notice .
1. If removed, install the transfer case mounting studs.

   Tighten:  Tighten the mounting studs to 31 N.m (23 lb ft).

Fig 2: View Of Front Transfer Case Bench Mount
Courtesy of GENERAL MOTORS CORP.
2. Using the adapter studs, attach the J 45759  to the front transfer case. 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: Seal For Shift Detent Lever Shaft
Courtesy of GENERAL MOTORS CORP.
4. Install the seal for the shift detent lever shaft. The seal will install using hand pressure. The spring side, or opened side, of the seal faces outward.
Fig 4: Vent & Front Case Half
Courtesy of GENERAL MOTORS CORP.
5. If the vent is removed, apply pipe sealant GM P/N 12346004 (Canadian P/N 10953480) to the threads on the vent.
6. Install the vent.

   Tighten:  Tighten the vent to 6 N.m (53 lb in).

Fig 5: Annulus Gear & Front Case Half
Courtesy of GENERAL MOTORS CORP.
7. Install the annulus gear in the front case half.
Fig 6: Locating Retaining Ring For Annulus Gear
Courtesy of GENERAL MOTORS CORP.
8. Install a NEW retaining ring for the annulus gear.
Fig 7: Installing Input Shaft Bearing
Courtesy of GENERAL MOTORS CORP.
IMPORTANT: Lubricate all of the bearings and bearing journals with transfer case fluid during installation.
9. Install the input shaft bearing in the front case half.
   • Use a hammer and a brass drift only on the outer bearing race.
   • Ensure the bearing is kept square to the bore while installing.
Fig 8: Aligning Brass Drift On Outer Bearing Race
Courtesy of GENERAL MOTORS CORP.
10. Install the front bearing for the front output shaft in the front case half.
    • Use a hammer and a brass drift only on the outer bearing race.
    • Ensure the bearing is kept square to the bore while installing.
Fig 9: Installing Cup Plug
Courtesy of GENERAL MOTORS CORP.
11. If it is a new shaft, or if the cup plug was removed, apply threadlocker GM P/N 12345382 (Canadian P/N 10953489) to the cup plug.
12. Using a suitable driver, install the cup plug in the front output shaft. Install the cup plug 1 mm (0.039 in) from flush with the end of the shaft.
Fig 10: Front Output Shaft Assembly
Courtesy of GENERAL MOTORS CORP.
13. Install the front output shaft assembly.
Fig 11: Installing Mainshaft Front Support Bearing Using J 42176 & J 45757
Courtesy of GENERAL MOTORS CORP.
14. Using the J 42176  (1) and the J 45757  (2), install the mainshaft front support bearing in the high/low planetary carrier assembly.
Fig 12: High/Low Planetary Carrier
Courtesy of GENERAL MOTORS CORP.
15. Install the high/low planetary carrier.
Fig 13: Input Shaft Thrust Washer
Courtesy of GENERAL MOTORS CORP.
16. Lubricate the input shaft thrust washer with J 36850  or equivalent. See Special Tools .
17. Install the input shaft thrust washer.
Fig 14: Range Shift Fork Range Shift Sleeve
Courtesy of GENERAL MOTORS CORP.
18. Install new shift fork pads, if removed.
19. Install the range shift sleeve in the range fork.
Fig 15: High/Low Range Sleeve & High/Low Range Shift Fork
Courtesy of GENERAL MOTORS CORP.
20. Align the gear teeth on the range shift sleeve to the planetary carrier.
21. Install the range shift fork and the range shift sleeve.
Fig 16: Identifying Oil Pump Journal Shoulder & Planetary Carrier
Courtesy of GENERAL MOTORS CORP.
IMPORTANT: There was a mid year production change in the design to the mainshaft and the drive sprocket. If the mainshaft or the drive sprocket is found faulty during inspection, it may require the replacement of both components. If the drive sprocket and the mainshaft are the older designs and either component requires replacement, both the mainshaft and drive sprocket must be replaced as a kit. The replacement components will only be the new design. If the mainshaft and the drive sprocket are the new design, the components can be replaced individually. Assembling an old design with a new design component will cause a drivability concern.
22. Inspect the mainshaft to ensure if it is the old design or new design. Measure the distance from the oil pump journal shoulder (A) to the end of the splines for the planetary carrier (B). The measurement for the old design mainshaft is 114.53-114.73 mm (4.509-4.517 in). The measurement for the new design mainshaft is 115.44-115.64 mm (4.545-4.553 in).
Fig 17: View of Older & Newer Design of Sprocket
Courtesy of GENERAL MOTORS CORP.
23. Inspect the drive sprocket to identify if it is the older design (1) or the newer design (2).

    There is only a slight difference to the drive sprocket on the rear surface. If the rear of the sprocket is almost flat, it is the old design (1). If the rear of the sprocket has a slight step of approximately 1 mm (0.039 in), it is the new design (2).

Fig 18: Identifying Mainshaft
Courtesy of GENERAL MOTORS CORP.
24. Install the mainshaft.
Fig 19: Expanded View Of Shift Detent Lever Assembly
Courtesy of GENERAL MOTORS CORP.
25. Assemble the shift detent lever assembly.
    1. Mount the spring (3), by one tab, in a vise.
    2. Install the sleeve (2) in the spring (3).
    3. Install the shaft (4) partially in the spring (3).
    4. Install the shift detent lever cam (1) on the shaft (4).
    5. Rotate the spring (3) and install the tab on the shift detent lever cam between the spring tabs.
    6. Finish installing the shaft, aligning the lever on the shaft between the spring tabs.
Fig 20: Shift Detent Lever Assembly
Courtesy of GENERAL MOTORS CORP.
NOTE: In order to prevent component damage, properly remove and install the shift detent lever shaft assembly. When removing or installing the shift detent lever shaft assembly, keep the shaft straight and do not tilt. Tilting the shift detent lever shaft assembly in the transfer case housing will break the tip on the end of the shaft.
26. Install the shift detent lever assembly.
    1. Install the shift detent lever assembly straight, with the tip into the hole in the case.
    2. Rotate the high/low shift fork to position the shift fork roller in the shift detent lever slot.
Fig 21: Shift Fork Shaft
Courtesy of GENERAL MOTORS CORP.
27. Install the shift fork shaft.
Fig 22: Locating Oil Pump Hose & Screen
Courtesy of GENERAL MOTORS CORP.
28. Connect the oil pump hose to the oil pump screen.
29. Connect the oil pump hose to the oil pump.
Fig 23: Expanded View Of Oil Pump Assembly
Courtesy of GENERAL MOTORS CORP.
30. Install the oil pump assembly with the hose and screen.
    1. Align the square boss of the oil pump gear with the flat area on the mainshaft.
    2. Install the oil pump in the slot of the front case half. Ensure the wear clip is on the oil pump.
    3. Install the oil pump screen in the front case half.
Fig 24: Identifying Magnet
Courtesy of GENERAL MOTORS CORP.
31. Install the magnet.
Fig 25: Inner Lockup Hub
Courtesy of GENERAL MOTORS CORP.
32. Install the inner lockup hub.
Fig 26: Illustrating Lockup Shift Assembly Components
Courtesy of GENERAL MOTORS CORP.
33. If necessary, assemble the lockup shift assembly.
    1. Install the spring in the sleeve.
    2. Install the hub, with the external tabs, towards the spring.
    3. Install the retainer ring in the sleeve.
Fig 27: Lockup Mode Shift Fork & Lockup Shift Assembly
Courtesy of GENERAL MOTORS CORP.
34. Install the lockup mode shift fork to the lockup shift assembly.
Fig 28: Identifying Lockup Shift Assembly & Lockup Mode Shift Fork
Courtesy of GENERAL MOTORS CORP.
35. Install the lockup shift assembly and lockup mode shift fork.
    • Slide the shift fork over the shift fork shaft.
    • Turn the mainshaft to align the slot on the inner lockup hub with the large tooth area on the lockup shift assembly hub.
Fig 29: Drive Sprocket Thrust Washer
Courtesy of GENERAL MOTORS CORP.
36. Lubricate the drive sprocket thrust washer with J 36850  or equivalent. See Special Tools .
37. Install the drive sprocket thrust washer.
Fig 30: Drive Chain & Sprockets
Courtesy of GENERAL MOTORS CORP.
IMPORTANT: If using the chain and sprockets again, ensure to align the marks of the drive chain and sprockets.
38. Install the drive chain and sprockets.
    • The blue link on the chain faces up.
    • Align the drive sprocket engagement teeth with the lockup shift assembly hub teeth.
Fig 31: Front Sun Gear
Courtesy of GENERAL MOTORS CORP.
39. Install the front sun gear.
Fig 32: Aligning Marks On Pinion Gears
Courtesy of GENERAL MOTORS CORP.
IMPORTANT: The planetary differential gears are timed to the sun gears. If the gears are not timed properly, the differential will not rotate without binding.
40. With the rear side of the planetary differential facing up, align the marks on the pinion gears. Position the alignment marks with an area on the planetary differential that can be reference for all gears.
Fig 33: Planetary Differential Assembly
Courtesy of GENERAL MOTORS CORP.
41. Install the planetary differential assembly.
    • Do not rotate the planetary differential pinion gears when installing.
    • Ensure the alignment marks are still in position.
    • The single row pinion gears face rearward, or up. The double row pinion gears face forward, or down.
Fig 34: Locating Rear Output Shaft Thrust Washer
Courtesy of GENERAL MOTORS CORP.
42. Lubricate the rear output shaft thrust washer with J 36850  or equivalent. See Special Tools .
43. Install the thrust washer.
Fig 35: Rear Sun Gear
Courtesy of GENERAL MOTORS CORP.
44. Install the rear sun gear.
    • The shoulder side of the gear faces up.
    • Do not rotate the differential pinion gears.
Fig 36: Checking Planetary Differential Pinion Gear Rotation With Rear Output Shaft
Courtesy of GENERAL MOTORS CORP.
45. Temporarily install the rear output shaft to the planetary differential and the rear sun gear.
46. Rotate the rear output shaft three or four revolutions to rotate the planetary differential pinion gears. If properly aligned, the pinion gears will rotate freely, there will be no binding.
47. Remove the rear output shaft without disturbing the rear sun gear.
Fig 37: Identifying Shift Fork Shaft Spring
Courtesy of GENERAL MOTORS CORP.
48. Install the shift fork shaft spring.
Fig 38: Installing Front Output Shaft Rear Bearing
Courtesy of GENERAL MOTORS CORP.
49. Install the front output shaft rear bearing in the rear case half.
    • Use a hammer and a brass drift only on the outer bearing race.
    • Ensure the bearing is kept square to the bore while installing.
Fig 39: Installing Rear Output Shaft Bearing Using Hydraulic Press & J 22912-01
Courtesy of GENERAL MOTORS CORP.
50. Using a hydraulic press and the J 22912-01  , install the rear output shaft bearing.
    • The retaining ring groove on the bearing goes toward the input end or forward.
    • Use a suitable press plate on the end of the rear output shaft.
    • Ensure the bearing is supported on the inner race.
Fig 40: Identifying Rear Output Shaft Bearing Retaining Ring
Courtesy of GENERAL MOTORS CORP.
51. Install a NEW retaining ring for the rear output shaft bearing.
Fig 41: Installing NEW Speed Reluctor Wheel Using Hydraulic Press
Courtesy of GENERAL MOTORS CORP.
52. Using a hydraulic press, install a NEW speed reluctor wheel.
Fig 42: Installing Mainshaft Rear Support Bushing In Rear Output Shaft
Courtesy of GENERAL MOTORS CORP.
53. Using J 42176  (1) and J 45757  (2), install the mainshaft rear support bushing in the rear output shaft. See Special Tools .
Fig 43: Identifying Rear Output Shaft & Outer Retaining Ring
Courtesy of GENERAL MOTORS CORP.
54. Install the rear output shaft in the rear case half.
    1. Spread the rear output shaft rear bearing outer retaining ring.
    2. Install the rear output shaft bearing outer retaining ring until it is seated in the bearing groove.
Fig 44: Applying RTV Sealant GM P/N 12345739 To Mating Surfaces Of Front Case Half
Courtesy of GENERAL MOTORS CORP.
IMPORTANT:
• Ensure that both the sealing surfaces on the front and rear case halves are free of dirt, oil, and cleaning solvent.
• Ensure the locating pins are installed in the case halves.
55. Install the locating pins in the front case and rear case half, if necessary.
56. Apply a 3.175 mm (1/8 in) bead of RTV Sealant GM P/N 12345739 (Canadian P/N 10953541) or equivalent to the mating surfaces of the front case half.
Fig 45: Rear Case Half
Courtesy of GENERAL MOTORS CORP.
57. Lower the rear case half into place.

    The rear output may require rotating to align the teeth with the planetary differential.

Fig 46: Identifying Transfer Case Retaining Bolts
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. New nylon coated case bolts and aluminum washers must be used. 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.
58. Inspect the nylon coating on the case bolts for cuts or tears.
59. Replace the case bolts if there is any damage to the nylon coating.
IMPORTANT: The case bolts are self-tapping. They must be hand started. Do not use power assisted tools to install the bolts.
60. Install the case bolts with washers, and the brackets.

    Tighten:  Tighten the case bolts to 21 N.m (15 lb ft).

Fig 47: Installing Vehicle Speed Sensor With New O-Ring Seal
Courtesy of GENERAL MOTORS CORP.
61. Install the vehicle speed sensor with a new O-ring seal.

    Tighten:  Tighten the speed sensor to 17 N.m (13 lb ft).

Fig 48: Applying RTV Sealant GM P/N 12345739 To Sealing Surface Of Encoder Motor Assembly
Courtesy of GENERAL MOTORS CORP.
62. Apply a 3.175 mm (1/8 in) bead of RTV Sealant GM P/N 12345739 (Canadian P/N 10953541) or equivalent to the sealing surface of the encoder motor assembly.
63. Install the encoder motor assembly. Rotate the shift detent lever to align to the encoder motor.
64. Loosely install the encoder motor mounting bolts.
65. Loosely install the encoder motor bracket bolt.

    Tighten: 

    • Tighten the encoder motor mounting bolts to 10 N.m (89 lb in).
    • Tighten the encoder motor bracket bolt to 10 N.m (89 lb in).

Fig 49: Installing Rear Output Shaft Seal
Courtesy of GENERAL MOTORS CORP.
66. Using J 45756  , install the rear output shaft seal. See Special Tools .
Fig 50: Drain Plug & Fill Plug
Courtesy of GENERAL MOTORS CORP.
67. Apply pipe sealant GM P/N 12346004 (Canadian P/N 10953480) to the threads on the drain plug and fill plug.
68. Install the drain plug and the fill plug.

    Tighten:  Tighten the drain plug and fill plug to 25 N.m (18 lb ft).

Fig 51: Installing Front Output Shaft Seal Using J 43484 & J 8092
Courtesy of GENERAL MOTORS CORP.
69. Using the J 43484  (2) and the J 8092  (1), install the front output shaft seal.
Fig 52: Installing The Front Input Shaft Seal Using J 42738
Courtesy of GENERAL MOTORS CORP.
70. Using the J 42738  , install the front input shaft seal. See Special Tools .
71. Remove the transfer case from the J 45759  . See Special Tools .