Case Extension Replacement

Case Extension Replacement

^ Tools Required
- J25025-7A Dial Indicator Post
- J28585 Snap Ring Remover
- J8001 Dial Indicator

Removal Procedure
1. Install the engine support fixture
2. Remove the right drive axle.
3. Raise the left side of the powertrain (the transmission side) 25.4 mm (1 inch) above the powertrain resting position with the adjusting screws.
4. Raise the vehicle. Refer to Vehicle Lifting.
5. Support the vehicle with safety stands.
6. Remove the wiring harness.
7. Remove the right transmission to engine brace.
8. Disconnect the vehicle speed sensor connector.
9. Remove the ground wire from the case.





10. Remove the following parts from the case extension:
^ Five 13 mm bolts (128, 129)
^ One 15 mm stud (127)
11. Remove the case extension (134) and the seal (126).
12. Remove the roller thrust bearing (132) and the selective washer (133)





13. Remove the 8 mm scavenge tube bolt.
14. Remove the scavenge tube by prying on the differential.
15. Remove the scavenge tube seal.

Installation Procedure





1. Inspect the scavenge tube (54) for damage and clogging.





2. Install the scavenge tube seal into the case.
3. Install the scavenge tube into the scavenge tube seals located in the case and in the driven sprocket support. Tap the scavenge tube lightly with a plastic hammer to ensure a tight fit in both seals.

Notice: Refer to Fastener Notice in Service Precautions.

4. Install the scavenge tube bolt.
^ Tighten the bolt to 8 - 14 Nm (6 - 10 ft. lbs.).





5. Inspect the case to case extension seal (126).
6. Inspect the case extension mating surface for damage.





7. Install the following parts:
^ The selective washer (133)
^ The thrust washer (132)
^ The case extension seal (126)
^ The case extension (134)





8. Apply pipe thread sealant GM P/N 12346004 to bolt threads before installation. Install the case extension bolts (128, 129).
9. Hand tighten the bolts (128, 129) until the case extension is seated onto the case.





10. Install the long J25025-7A and the J8001.
11. Position the dial indicator with the stem contacting the output shaft (112). Set the dial indicator to zero.
12. Insert the J28585 through the vehicle speed sensor bore and lift the speed sensor rotor for measurement. Protect the bore with a piece of wood or a suitable piece of plastic.
13. Proper end play clearance is 0.15 - 0.65 mm (0.006 - 0.026 inch).
14. Record the measured specification and, if necessary, adjust the clearance with the proper thickness selective thrust washer and reassemble. Refer to step 3.
15. Remove the dial indicator set and the post.

Notice: Refer to Fastener Notice in Service Precautions.





16. Install the stud (127).
^ Tighten the bolt (128) and the stud (127) to 50 - 55 Nm (37 - 40 ft. lbs.).
^ Tighten the bolt (129) to 20 - 27 Nm (15 - 20 ft. lbs.).
17. Connect the vehicle speed sensor.
18. Install the ground wire to case.
19. Install the transmission brace.
20. Install the wiring harness.
21. Install the right drive axle.
22. Remove the safety stands.
23. Lower the vehicle.
24. Remove the engine support fixture.
25. Fill the transmission with fluid.
26. Check the fluid level.