Transfer Case Disassemble

Tools Required

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

Fig 1: View Of Rear Case
Courtesy of GENERAL MOTORS CORP.
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 2: Locating Gearshift Lever Case
Courtesy of GENERAL MOTORS CORP.
4. Remove the following components from the rear case:
   • The 5 bolts
   • The gearshift bracket
   • The (1)
Fig 3: View Of Select Return Components In Rear 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 4: Driving Roll Pin From Reduction Shift Yoke
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 5: Locating Rear Case Bolts
Courtesy of GENERAL MOTORS CORP.
8. Remove the 15 rear case bolts.
Fig 6: Separating The Rear Case From The Center Case Using J 37637
Courtesy of GENERAL MOTORS CORP.
9. Separate the rear case from the center case using a J 37637  .

   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 7: Using J 34757 To Remove/Install Speedometer Drive Gear
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 8: Locating Drive Gear Ball In Rear Output Shaft
Courtesy of GENERAL MOTORS CORP.
12. Carefully remove the drive gear ball from the rear output shaft.
Fig 9: Removing Rear Output Shaft Rear Bearing C-Clip
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 10: Removing Rear Output Shaft Rear Bearing From Rear Output Shaft Using J 8433 & J 37756
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 11: Identifying Drive Sprocket Bushing & Bearing
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 12: Locating Synchronizer Plate
Courtesy of GENERAL MOTORS CORP.
16. Remove the following components from the rear output shaft:
    • 2 screws (2)
    • The synchronizing plate (1)
Fig 13: Locating Drive Sprocket & Chain
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 14: Removing The Rear Output Shaft Oil Seal From The Rear Case J 26941 & J 23907
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 15: Locating Oil Guide & Bolt
Courtesy of GENERAL MOTORS CORP.
19. Remove the following components from the rear case:
    • One bolt (1)
    • The oil guide
Fig 16: Removing Rear Output Shaft Needle Bearing From Case Using J 26941
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 17: Locating Countershaft Case Plate Bolt
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 18: View Of Front Case Bolts
Courtesy of GENERAL MOTORS CORP.
22. Remove the 9 front case bolts (1) from the front case.
Fig 19: Identifying Countershaft Assembly In Center Case
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 20: Exploded View Of Countershaft Assembly
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 21: Removing Countershaft Friction Ring
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 22: Identifying Center Case Components
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 23: View Of Reduction Shift Components
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 24: Identifying Front Drive Shift Components
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 25: Locating Interlock Ball In Center Case Passage
Courtesy of GENERAL MOTORS CORP.
34. Remove the interlock ball (1) from the center case passage.
Fig 26: View Of Reduction Hub C-Clip
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 27: Using Plastic Mallet To Remove Rear Output Shaft
Courtesy of GENERAL MOTORS CORP.
37. Use a plastic mallet in order to remove the rear output shaft from the center case.
Fig 28: Removing The Rear Output Shaft Front Bearing From The Rear Output Shaft J 22912-01
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 29: Removing Front Output Shaft & Bearings
Courtesy of GENERAL MOTORS CORP.
39. Using a plastic mallet, remove the front output shaft and the bearings (1) from the center case.
Fig 30: Identifying Case Gutter & Bolt
Courtesy of GENERAL MOTORS CORP.
40. Remove the following components from the center case:
    • One bolt (1)
    • The case gutter
Fig 31: Removing The Front Output Shaft Oil Seal From The Center Case J 26941 & J 23907
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 32: Using J 26941 To Remove Front Output Shaft Needle Bearing
Courtesy of GENERAL MOTORS CORP.
42. Using J 26941  and a hammer, remove the front output shaft needle bearing from the center case.
Fig 33: Removing Front Output Shaft Bearings Using J 22912-O1 & J 34844
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 34: Loosening Center Bearing Snap Ring On Input Gear
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 35: Removing Input Gear Assembly From Front Case
Courtesy of GENERAL MOTORS CORP.
45. Using a plastic mallet, remove the input gear assembly from the front case.
Fig 36: Removing Input Gear Seal With J 23907
Courtesy of GENERAL MOTORS CORP.
46. Using J 26941  with J 23907  , remove the input gear oil seal from the front case.
Fig 37: Removing Side Bearing Snap Ring
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 38: View Of J 22912-O1 & J 28406 Removing The Input Gear Bearing From The Input Gear
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 39: Identifying Front Drive Shaft Components
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 40: Inspection Areas Of Clutch Hubs & Sleeves
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 41: Checking Springs Using J 26900-5
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 42: Measuring Shift Fork-To-Clutch Clearance With Feeler Gage
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 43: Identifying Synchronizer Outer Ring
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 44: Measuring Key Slot Width
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).