Transfer Case Disassemble

Tools Required 

• J 37637-A  Case Separator
• J 8433  Bearing Puller
• J 37756  Output Shaft Bearing Puller Adapter
• J 26941  Needle Bearing Puller
• J 23907  Slide Hammer
• J 34757  Output Shaft Ring Remover
• J 39497  Friction Ring Remover and Installer
• J 22912-O1  Split Plate
• J 34844  Front Shaft Bearing Remover
• J 28406  Input Gear Bearing Remover
• J 26900-5  Vernier Caliper

1. Remove the following components from the rear case:
   • The four-wheel drive switch
   • The steel ball
   • The O-ring
2. Remove the following components from the rear of the case (if equipped):
   • The four-wheel drive low switch and the steel ball
   • The O-ring
3. Remove the following components from the rear case:
   • One bolt
   • The speedometer driven gear case
   • The O-ring
   Fig 1: View Of Rear Case

   Courtesy of GENERAL MOTORS CORP.
4. Remove the following components from the rear case:
   • The 5 bolts
   • The gearshift bracket
   • The gearshift lever case (1)
   Fig 2: Gearshift Lever Case

   Courtesy of GENERAL MOTORS CORP.
5. Remove the following components from the rear case (6):
   • The select return spring bolt (1)
   • The washer (2)
   • The select return spring (3)
   • The select return ball (4)
   • The select return pin (5)
   Fig 3: Removing Select Return Spring & Components
   Courtesy of GENERAL MOTORS CORP.
   IMPORTANT: After you remove the rear case, use a magnet in order to extract the pin from the case.
6. Using a standard drift punch and a hammer (1), drive the roll pin from the reduction shift yoke. This procedure will cause the pin to fall into the transfer case assembly.
7. Slide the reduction shift yoke rearward. Pull the reduction shift yoke off the reduction shift shaft and out of the rear case.
   Fig 4: Driving Out Roll Pin Using Drift Punch & Hammer

   Courtesy of GENERAL MOTORS CORP.
8. Remove the 15 rear case bolts.
   Fig 5: Removing Rear Case Bolts

   Courtesy of GENERAL MOTORS CORP.
9. Separate the rear case from the center case using a J 37637-A. 

   Using a magnet, remove the shift yoke roll pin from inside the rear transfer case.

10. Remove the selective shim from the top of the rear output shaft rear bearing.
    Fig 6: Separating Rear Case From Center Case Using J 37637-A

    Courtesy of GENERAL MOTORS CORP.
11. Use J 34757  in order to remove the following components from the rear output shaft:
    • The speedometer drive gear C-clip
    • The speedometer drive gear
    Fig 7: Installing J 34757

    Courtesy of GENERAL MOTORS CORP.
12. Carefully remove the drive gear ball from the rear output shaft.
    Fig 8: Removing Drive Gear Ball From Rear Output Shaft

    Courtesy of GENERAL MOTORS CORP.
13. Use J 34757  in order to remove the rear output shaft rear bearing C-clip from the rear output shaft.
    Fig 9: Removing Rear Output Shaft Rear Bearing C-Clip

    Courtesy of GENERAL MOTORS CORP.
14. Use J 8433  with J 37756  in order to remove the rear output shaft rear bearing from the rear output shaft.
    Fig 10: Removing Rear Output Shaft Rear Bearing Using J 37756 & J 8433

    Courtesy of GENERAL MOTORS CORP.
    IMPORTANT: Do not lose the rear output shaft washer ball underneath the drive sprocket bushing during the sprocket bushing removal.
15. Remove the following components:
    • The drive sprocket bushing (1) output shaft
    • The drive sprocket needle bearing (2) output shaft
    Fig 11: Removing Drive Sprocket Bushing & Needle Bearing

    Courtesy of GENERAL MOTORS CORP.
16. Remove the following components from the rear output shaft:
    • 2 screws (2)
    • The synchronizing plate (1)
    Fig 12: Removing Synchronizing Plate & Screws

    Courtesy of GENERAL MOTORS CORP.
17. Remove the following drive components from the rear output shaft and the front output shaft:
    • The drive sprocket (2)
    • The drive chain (1)
    • The rear output shaft washer ball
    Fig 13: Removing Drive Sprocket & Drive Chain

    Courtesy of GENERAL MOTORS CORP.
18. Use J 26941  with J 23907  in order to remove the rear output shaft oil seal from the rear case.
    Fig 14: Removing Rear Output Shaft Oil Seal Using J 26941 With J 23907

    Courtesy of GENERAL MOTORS CORP.
19. Remove the following components from the rear case:
    • One bolt (1)
    • The oil guide
    Fig 15: Removing Oil Guide & Bolt

    Courtesy of GENERAL MOTORS CORP.
20. Use J 26941  and a hammer in order to remove the rear output shaft needle bearing from the rear case.
    Fig 16: Removing Rear Output Shaft Needle Bearing From Rear Case

    Courtesy of GENERAL MOTORS CORP.
21. Remove the following components from the front case:
    • One bolt (2)
    • One washer
    • The countershaft case plate (1)
    Fig 17: Removing Countershaft Case Plate & Bolt

    Courtesy of GENERAL MOTORS CORP.
22. Remove the 9 front case bolts (1) from the front case.
    Fig 18: Removing Front Case Bolts

    Courtesy of GENERAL MOTORS CORP.
23. Separate the front case from the center case (1).
24. Remove the countershaft assembly (3) from the center case.
    Fig 19: Separating Front Case From Center Case

    Courtesy of GENERAL MOTORS CORP.
    IMPORTANT: Do not lose the countershaft washer balls which come out from between the countershaft (9) and the countershaft washers (1,7).
25. Remove the following components from the countershaft (9):
    • The countershaft washers (1,7)
    • The washer balls (3)
26. Remove the following components from the countershaft:
    • The counter gear (6)
    • The countershaft needle bearings (4,8)
    • The countershaft spacer (5)
27. Inspect the countershaft friction ring for excessive wear or damage. Replace as necessary.
28. Inspect the countershaft O-ring for cuts or other damage. Replace as necessary.
    IMPORTANT: Do NOT remove either the countershaft friction ring (10) or the O-ring (2) unless absolutely necessary. If you remove either one, replace with new components.
29. Remove the countershaft O-ring from the countershaft.
    Fig 20: Countershaft Components

    Courtesy of GENERAL MOTORS CORP.
30. Use J 39497  and a press arbor (2) in order to remove the countershaft friction ring (1) from the countershaft (3).
    Fig 21: Removing Countershaft Friction Ring Using J 39497 & Press Arbor

    Courtesy of GENERAL MOTORS CORP.
31. Remove the following components from the center case:
    • The 1 rubber plug (1)
    • The 2 locating screws (4)
    • The 1 washer
    • The 2 locating springs (3)
    • The 2 locating balls (2)
    Fig 22: Removing Rubber Plug, Locating Screws, Locating Springs & Locating Balls

    Courtesy of GENERAL MOTORS CORP.
    IMPORTANT: Observe the alignment marks on the following components in order to ensure correct alignment during assembly:

    • The caged needle bearing
    • The reduction clutch sleeve and hub
    • The front drive clutch sleeve and hub

    If no alignment marks are present, scribe new marks on these components.

32. Remove the following components from the rear output shaft, in front of the center case:
    • The reduction shift shaft (2)
    • The reduction shift fork (1)
    • The reduction clutch sleeve (3)
    Fig 23: Removing Reduction Shift Shaft, Shift Fork & Clutch Sleeve

    Courtesy of GENERAL MOTORS CORP.
33. Remove the following components from the rear output shaft, in the rear of the center case:
    • The front drive shift shaft (4)
    • The front drive shift fork (1)
    • The front drive clutch sleeve (2)
    • The front drive clutch hub (3)
    Fig 24: Removing Front Drive Shift Shaft, Shift Fork, Clutch Sleeve & Clutch Hub

    Courtesy of GENERAL MOTORS CORP.
34. Remove the interlock ball (1) from the center case passage.
    Fig 25: Removing Interlock Ball From Center Case Passage

    Courtesy of GENERAL MOTORS CORP.
35. Use J 34757  in order to remove the reduction hub C-clip (3) from the rear output shaft.
36. Remove the following components from the rear output shaft.
    • The reduction clutch hub (2)
    • The low output gear
    • The low output gear needle bearing (1)
    Fig 26: Removing Reduction Hub C-Clip, Reduction Clutch Hub & Low Output Gear Needle Bearing

    Courtesy of GENERAL MOTORS CORP.
37. Use a plastic mallet in order to remove the rear output shaft from the center case.
    Fig 27: Removing Rear Output Shaft From Center Case Using Plastic Mallet

    Courtesy of GENERAL MOTORS CORP.
38. Use J 22912-O1  and a press arbor in order to remove the rear output shaft front bearing from the rear output shaft.
    Fig 28: Removing Rear Output Shaft Front Bearing Using J 22912-O1

    Courtesy of GENERAL MOTORS CORP.
39. Using a plastic mallet, remove the front output shaft and the bearings (1) from the center case.
    Fig 29: Removing Front Output Shaft & Bearings Using Plastic Mallet

    Courtesy of GENERAL MOTORS CORP.
40. Remove the following components from the center case:
    • One bolt (1)
    • The case gutter
    Fig 30: Locating Center Case Bolts

    Courtesy of GENERAL MOTORS CORP.
41. Use J 26941  with J 23907  in order to remove the front output shaft oil seal from the center case.
    Fig 31: Removing Front Output Shaft Oil Seal Using J 26941 With J 23907

    Courtesy of GENERAL MOTORS CORP.
42. Using J 26941  and a hammer, remove the front output shaft needle bearing from the center case.
    Fig 32: Removing Front Output Shaft Needle Bearing

    Courtesy of GENERAL MOTORS CORP.
43. Use J 22912-O1  with J 34844  and a press arbor in order to remove the front output shaft bearings from the front output shaft.
    Fig 33: Removing Front Output Shaft Bearings

    Courtesy of GENERAL MOTORS CORP.
44. Loosen the center bearing snap ring within the input gear. You cannot remove this snap ring at this time.
    Fig 34: Loosening Center Bearing Snap Ring

    Courtesy of GENERAL MOTORS CORP.
45. Using a plastic mallet, remove the input gear assembly from the front case.
    Fig 35: Removing Input Gear Assembly From Front Case Using Plastic Mallet

    Courtesy of GENERAL MOTORS CORP.
46. Using J 26941  with J 23907,  remove the input gear oil seal from the front case.
    Fig 36: Removing Input Gear Oil Seal From Front Case

    Courtesy of GENERAL MOTORS CORP.
    IMPORTANT: During gear assembly removal, the bearing may move, binding the snap ring in its groove. Apply light pressure with the mallet in order to slide the bearing back to its original position before you attempt to remove the snap ring.
47. Using snap ring pliers, remove the side bearing snap ring (1) from the input gear.
    Fig 37: Removing Side Bearing Snap Ring Using Snap Ring Pliers

    Courtesy of GENERAL MOTORS CORP.
48. Use J 22912-O1  with J 28406  and a press arbor in order to remove the input gear bearing from the input gear.
49. Remove the center bearing snap ring from the input gear.
    Fig 38: Removing Input Gear Bearing From Input Gear

    Courtesy of GENERAL MOTORS CORP.
50. Remove one roll pin from the reduction shift fork.
51. Remove the reduction roll fork from the reduction shift shaft.
52. Remove the following components from the front drive shift shaft:
    • The two E-clips (6)
    • The shaft stop washer (5)
    • The front drive shift fork (4)
    • The front drive fork spring (3)
    IMPORTANT: Careful cleaning of the component mating surfaces will ensure proper case sealing.
53. Clean the following components with solvent and dry thoroughly:
    • The front case
    • The rear case
    • The center case
54. Clean all of the internal components with solvent and dry thoroughly.
55. Inspect the following components for cracks or porosity:
    • The front case
    • The rear case
    • The center case
    • The gearshift lever case

    Replace as necessary.

56. Inspect the drive teeth and the clutching teeth of all of the gears and sprockets for the following conditions:
    • Broken teeth
    • Chipped teeth
    • Gear clash damage
57. Inspect the shift shafts and the forks for the following conditions:
    • Excessive wear
    • Distortion

    Replace as necessary

58. Inspect each ball bearing for smooth rotation. If the rotation is abnormal, replace the ball bearing.
59. Inspect the needle bearing and the bearing contacting surface for damage. Replace as required.
60. Inspect the gear tooth surface and the shift mechanism. Correct an abnormal mechanism or replace as required.
61. Inspect the drive chain and the sprockets for abnormal wear or damage. Replace as required.
62. Inspect the oil seal for leakage and inspect the oil seal lip for excessive hardness.

    Inspect the corresponding surface of the shaft where the oil seal lip contacts. Correct an abnormal condition or replace as required.

63. Inspect the gear tooth surface of the speedometer drive gear. Replace a damaged gear.
    Fig 39: Front Drive Shift Shaft Components

    Courtesy of GENERAL MOTORS CORP.
64. Inspect the clutch hubs (1) and the sleeves (2) for the following conditions:
    • Poor fit
    • Cracked teeth (3)
    • Broken teeth

    Replace as necessary

    Fig 40: Inspecting Clutch Hubs & Sleeves

    Courtesy of GENERAL MOTORS CORP.
65. Inspect the locating springs for the following conditions:
    • Weakness
    • Distortion

    Replace as necessary

66. Use J 26900-5  in order to measure each locating spring.

    Measurement 

    Standard spring length is 19.5 mm (0.768 in). If a spring length measures below 18.0 mm (0.709 in), replace the springs as necessary.

    Fig 41: Measuring Spring Length With J 26900-5

    Courtesy of GENERAL MOTORS CORP.
67. Use a feeler gage in order to measure the shift fork-to-clutch sleeve clearance.

    Measurement 

    The maximum shift fork-to-clutch sleeve clearance is 1.0 mm (0.039 in).

    If the clearance is greater than 1.0 mm (0.039 in), replace the shift fork and the clutch sleeve as necessary.

    Fig 42: Measuring Shift Fork-To-Clutch Sleeve Clearance

    Courtesy of GENERAL MOTORS CORP.
68. Assemble the following components:
    • The synchronizer outer ring (4)
    • The inner ring (2)
    • The cone (3)
69. Measure the step difference (1) between the outer ring and the inner ring.

    Measurement 

    The standard difference between the inner ring and the outer ring is 1.0-1.4 mm (0.039-0.055 in).

    Fig 43: Measuring Step Difference Between Outer Ring & Inner Ring

    Courtesy of GENERAL MOTORS CORP.
70. Measure the key slot width (2) in the synchronizer outer ring (1) and inspect each chamfered tooth of the gear and the synchronizer ring. If necessary, replace the outer ring.

Measurement 

The maximum slot width in the outer ring is 10.1 mm (0.397 in).

Fig 44: Measuring Key Slot Width In Synchronizer Outer Ring

Courtesy of GENERAL MOTORS CORP.