Transmission Disassemble

Tools Required

• J 8614-01  Flange and Pulley Holding Tool
• J 23907  Slide Hammer with Bearing Adapter
• J 36825  Output Shaft Oil Seal Remover - 4WD Models Only
• J 44707  T-Bar Push Puller
• J 44725  Gear Pack Assembly Fixture. See Special Tools .
• J 44726  2/3 Jaw Puller. See Special Tools .
• J 44730  Intermediate Case Puller Legs. See Special Tools .

1. Remove the drain plug and drain the transmission fluid.
   Fig 1: Removing Transmission Drain Plug

   Courtesy of GENERAL MOTORS CORP.
2. Position the transmission on the floor with the output shaft up. Use boards in order to allow for the protrusion of the input shaft.
   Fig 2: Positioning Transmission With Output Shaft Up

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3. If the transmission is equipped with a power take-off (PTO), remove the PTO.
4. Remove the shift control housing bolts.
   Fig 3: Removing Shift Control Housing Assembly

   Courtesy of GENERAL MOTORS CORP.
5. Remove the shift control housing assembly.
6. For RWD transmission, using the J 8614-01  , loosen the propeller shaft yoke nut.
   Fig 4: Loosening Propeller Shaft Yoke Nut

   Courtesy of GENERAL MOTORS CORP.
7. For RWD transmission, remove the propeller shaft yoke nut and discard.
8. Remove the propeller shaft yoke.
   Fig 5: Removing Propeller Shaft Yoke

   Courtesy of GENERAL MOTORS CORP.
9. Remove the shift shaft detent sleeve and the shift shaft detent plunger.
   Fig 6: Removing Shift Shaft Detent Plunger

   Courtesy of GENERAL MOTORS CORP.
NOTE: Refer to MACHINED SURFACE DAMAGE NOTICE in Cautions and Notices.
Fig 7: Removing VSS
Courtesy of GENERAL MOTORS CORP.
10. If RWD, remove the vehicle speed sensor (VSS) bolt and washer.
11. Remove the VSS and O-ring seal.
12. Remove and discard the O-ring seal.
13. Remove the 19 bolts retaining the rear case to the front case.
    Fig 8: Removing Rear Case Retaining Bolts

    Courtesy of GENERAL MOTORS CORP.
IMPORTANT: Do not separate the rear case from the intermediate case by using a pry bar between the cases. The cases have machined sealing surfaces.
Fig 9: Removing Rear Case
Courtesy of GENERAL MOTORS CORP.
14. Remove the rear case.
    • Use a soft-face hammer and hit up on the rear case.
    • The cases should come apart once the sealer is broken.
    • There are 2 dowel pins that may bind in the rear case.
    • The mainshaft rear bearing is a slip fit in the rear case and may bind if the case is not lifted up straight.
15. Remove the 2 bolts for the intermediate case.
    Fig 10: Removing Intermediate Case Bolts

    Courtesy of GENERAL MOTORS CORP.
16. Install the S-hooks in the webbing of the intermediate case to the locations shown.
    Fig 11: Installing S-Hooks & Chain To Intermediate Case

    Courtesy of GENERAL MOTORS CORP.

    Attach a suitable chain to the S-hooks.

17. Using a suitable lifting device, carefully remove the gear assembly from the front case.
    Fig 12: Removing Gear Assembly

    Courtesy of GENERAL MOTORS CORP.
IMPORTANT: The weight of the gear assembly is extended over the edge of the workbench. The weight may tip over or overload a standard metal workbench.
Fig 13: Identifying J 44725
Courtesy of GENERAL MOTORS CORP.
18. Secure the J 44725  (1) to a sturdy workbench. See Special Tools .
19. Position the gear assembly on the J 44725  . See Special Tools .
NOTE: When removing the roll pins from the shift shafts use a punch that is a slightly smaller diameter than the roll pin. Flaring of the shift shaft groove may occur if the punch binds. This will result in extra effort to remove the shift forks or shift control levers. When double roll pins are used, remove both of the roll pins at the same time. Support the shift component when removing the roll pins to prevent damage to the shift shafts. Do not reuse the roll pins after removal.
Fig 14: Removing Internal Shift Control Rear Lever Roll Pin
Courtesy of GENERAL MOTORS CORP.
20. Using a hammer and punch, remove the roll pins from the internal shift control rear lever.
21. Remove the internal shift control rear lever.
    Fig 15: Removing Internal Shift Control Rear Lever

    Courtesy of GENERAL MOTORS CORP.
22. Using a hammer and a punch, remove the roll pins for the internal shift control front lever.
    Fig 16: Removing Internal Shift Control Front Lever Roll Pin

    Courtesy of GENERAL MOTORS CORP.
23. Remove the internal shift control front lever.
    Fig 17: Removing Internal Shift Control Front Lever

    Courtesy of GENERAL MOTORS CORP.
    1. Turn the internal shift control front lever in order to clear the 2nd/3rd shift fork and the 4th/5th shift fork.
    2. Remove the shift shaft with the internal shift control front lever.
24. Using the J 36825  (1) and the J 23907  (2), remove the 4 shift shaft detent plugs.
    Fig 18: Using J 36825 & J 23907 To Remove Shift Shaft Detent Plugs

    Courtesy of GENERAL MOTORS CORP.
IMPORTANT: Only remove the plungers as needed for replacement.
Fig 19: Removing Shift Shaft Detent Spring & Plunger
Courtesy of GENERAL MOTORS CORP.
25. Remove the shift shaft detent springs and the shift shaft detent plungers. The plungers should only be removed if replacing the plungers. The plungers may be hard to come out now. After removing the shift shafts, the plungers will be easier to remove.
NOTE: When removing the roll pins from the shift shafts use a punch that is a slightly smaller diameter than the roll pin. Flaring of the shift shaft groove may occur if the punch binds. This will result in extra effort to remove the shift forks or shift control levers. When double roll pins are used, remove both of the roll pins at the same time. Support the shift component when removing the roll pins to prevent damage to the shift shafts. Do not reuse the roll pins after removal.
IMPORTANT: The 4th/5th shift fork and the 2nd/3rd shift fork do not require removal from the shift shafts for transmission disassembly. Do not remove the roll pins from the 4th/5th shift fork and the 2nd/3rd shift fork unless replacing the shift forks or the shift shafts.
26. Remove the following roll pins:
    • The 6th gear shift fork (1)
    • The 1st/reverse gear shift fork (2)
    Fig 20: Removing 6th Gear & 1st/Reverse Gear Shift Fork Roll Pins
    Courtesy of GENERAL MOTORS CORP.
27. Remove the 6th gear shift fork and shaft.
    Fig 21: Removing 6th Gear Shift Fork & Shaft

    Courtesy of GENERAL MOTORS CORP.
    1. Move the interlock plate in the 6th gear position by moving the plate toward the 1st/reverse shift shaft.
    2. Pull up on the shift shaft while tapping down on the shift fork with a soft-face hammer.
    3. Remove the shift fork and shaft from the 6th gear synchronizer assembly.
28. Remove the 1st/reverse shift fork and shaft.
    Fig 22: Removing 1st/Reverse Shift Fork & Shaft

    Courtesy of GENERAL MOTORS CORP.
    1. Move the interlock plate in the reverse gear shift position by moving the plate toward the 6th gear shift shaft.
    2. Pull up on the shift shaft while tapping down on the shift fork with a soft-face hammer.
    3. Remove the shift fork and shaft from the 1st/reverse gear synchronizer hub.
29. If 4WD, remove the retaining ring for the mainshaft rear bearing.
    Fig 23: Removing Mainshaft Rear Bearing Retaining Ring

    Courtesy of GENERAL MOTORS CORP.
30. Using the J 44726  , remove the gears from the mainshaft. See Special Tools .
    Fig 24: Removing Gears From Mainshaft Using J 44726

    Courtesy of GENERAL MOTORS CORP.
31. Remove the following components from the mainshaft:
    Fig 25: Removing Mainshaft Components

    Courtesy of GENERAL MOTORS CORP.
    1. The speed sensor reluctor wheel, RWD only (1)
    2. The mainshaft rear bearing (2)
    3. The reverse gear thrust washer (3)
    4. The reverse gear (4)
    5. The reverse gear bearings (5)
    6. The reverse gear bushing (6)
    7. The reverse gear synchronizer blocking ring (7)
    8. The 1st/reverse synchronizer assembly (8)
    9. The 1st gear synchronizer blocking ring (9)
    10. The 1st gear (10)
    11. The 1st gear bearings (11)
32. Remove the retaining ring for the 6th gear.
    Fig 26: Removing 6th Gear Retaining Ring

    Courtesy of GENERAL MOTORS CORP.
33. Remove the following components from the countershaft (4):
    Fig 27: Removing 6th Gear & Components

    Courtesy of GENERAL MOTORS CORP.
    1. The thrust washer (1)
    2. The 6th gear (2)
    3. The 6th gear bearing (3)
34. Remove the bolts for the shift interlock plate.
    Fig 28: Removing Shift Interlock Plate

    Courtesy of GENERAL MOTORS CORP.
35. Let the shift interlock plate rest on the shift shafts.
36. Install the J 44730  (2) to the J 44707  (1). See Special Tools .
    Fig 29: Installing J 44730 & J 44707

    Courtesy of GENERAL MOTORS CORP.
IMPORTANT: You will be using the intermediate case to pull off the 6th gear synchronizer hub and the 6th gear bushing. Ensure the J 44730  is properly located on the intermediate case. See Special Tools .
37. Install the J 44730  (2) on the intermediate case as shown. See Special Tools . The J 44730  needs to be aligned in order for the J 44707  to be centered on the mainshaft. See Special Tools .
38. Using the J 44730  (2) and the J 44707  (1) on the countershaft, remove the 6th gear synchronizer hub and 6th gear bushing.
    • The intermediate case will slide off the 2nd/3rd shift shaft and the 4th/5th shift shaft.
    • Keep the shift shafts straight in order to ensure the intermediate case does not bind on the shift shafts.
    • If the intermediate case starts to bind on the shift shafts, stop pulling.
    • Straighten the shift shafts in the intermediate case and continue pulling.
39. Remove the 6th gear bearing race (1).
    Fig 30: Removing 6th Gear Bearing Race & Synchronizer Assembly

    Courtesy of GENERAL MOTORS CORP.
40. Remove the 6th gear synchronizer assembly (2).
41. Remove the intermediate case from the mainshaft and the countershaft.
    Fig 31: Removing Intermediate Case

    Courtesy of GENERAL MOTORS CORP.
42. Remove the 6th gear spacer from the countershaft.
    Fig 32: Removing 6th Gear Spacer

    Courtesy of GENERAL MOTORS CORP.
43. Remove the 2nd/3rd shift fork and shaft, the 4th/5th shift fork and shaft, and the shift interlock plate from the mainshaft assembly.
    Fig 33: Removing 2nd/3rd & 4th/5th Shift Forks & Shafts

    Courtesy of GENERAL MOTORS CORP.
44. Remove the countershaft from the mainshaft by walking the countershaft away.
    Fig 34: Removing Countershaft

    Courtesy of GENERAL MOTORS CORP.