Launch Shudder Felt on Hard Acceleration (Replace Transmission Output Shaft Flange)

This bulletin is being revised to notify dealers that this bulletin ONLY applies to Automatic Transmissions. Please discard Corporate Bulletin Number 02-07-30-026.

Some customers may comment on a shudder felt in the vehicle on acceleration.

This condition may be caused by insufficient clearance between the transmission output shaft flange and the propshaft attaching bolts.

Important: This bulletin ONLY applies to automatic transmission equipped vehicles with RPO M82.

Replace transmission output shaft flange "A" with the newly designed transmission output shaft flange "B."

Important: With the vehicle properly supported on the hoist, shift the vehicle transmission out of the Park position into the Neutral position.

1. Raise and suitably support the vehicle. Refer to Lifting and Jacking the Vehicle in the General Information subsection of the Service Manual.



2. Remove the bolts securing the brace to the floor pan.
3. Remove the floor panel tunnel brace from the floor panel.
4. Position a jack stand or other suitable support under the front resonator of the exhaust system.
5. Remove the nuts securing the exhaust system to the catalytic converters on both sides.
6. Disconnect the exhaust system from the rubber hangers and remove the exhaust system from the vehicle.
7. Locate a suitable location from which a mechanic's wire support may be attached to support the front portion of the propshaft after you disconnect it from the transmission drive flange.




Important: Remove only the propeller shaft coupler-to-transmission flange bolts. Do NOT remove the coupler from the propeller shaft.

8. Remove the propeller shaft coupler-to-transmission flange bolts (2) and nuts (3). Slide the propshaft slightly rearward to clear the transmission output drive flange and attach the propshaft to the mechanic's wire.



9. Install the J 45012 to the transmission drive flange.
10. While holding the J 45012, remove the drive flange nut using the J 29873, a 30 mm socket or the equivalent.



11. Remove the drive flange thrust washer (4).
12. Remove the drive flange (2) using the J 45019.
13. Remove the drive flange O-ring seal (3) from the drive flange.
14. Remove the output shaft assembly retainer (1). This is a snap ring on the output shaft.




Important: To ensure proper adhesion and fastener retention if reusing the propeller shaft to flange nuts and bolts, the threads must be free of debris and/or oil residue prior to the application of threadlocker. Thoroughly clean the threads using Brake Clean, denatured alcohol or the equivalent (DO NOT USE CARB CLEANER. CARB CLEANER LEAVES AN OILY RESIDUE) and allow to dry. Apply High Temp-High Strength threadlocker LOCKTITE™ 272, GM P/N 12345493 (Canadian P/N 10953488), or the equivalent, to the propeller shaft to flange bolts. Ensure that there are no gaps in the threadlocker along the length of the filled area of the bolt. Allow the threadlocker to cure approximately ten minutes before installation.

15. Install a NEW output shaft assembly retainer (1). Position the retainer on the end of the output shaft splines. The retainer will be pushed to the proper depth as the drive flange is installed onto the output shaft.

Important: The transmission output shaft, the output shaft flange and the washer should be cleaned of all oil and oil residue with Brake Clean before installation.

16. Install the O-ring seal from the kit # 3 into the drive flange seal groove.
17. Install the drive flange (2) to the transmission output shaft.
18. Install the NEW drive flange thrust (wave) washer (4).

Important: The NEW nut included with the kit has pinkish/red compound on the treads. It is extremely important that this compound be left on the threads. In addition, a strip of LOCKTITE™ 242 (medium strength threadlocker BLUE), GM P/N 12345382 (Canadian P/N 10953489), be applied across the threads.

19. Install the J 45012 to the drive flange.
20. While holding the J 45012, install a NEW drive flange nut using the J 29873 .

Tighten
Tighten the drive flange nut to 60 N·m(44 lb ft).

21. Remove the J 45012 from the drive flange.

Important: To ensure proper adhesion and fastener retention if reusing the propeller shaft to flange nuts and bolts, the threads must be free of debris and/or oil residue prior to the application of threadlocker. Thoroughly clean the threads using Brake Clean, denatured alcohol or the equivalent (DO NOT USE CARB CLEANER. CARB CLEANER LEAVES AN OILY RESIDUE) and allow to dry. Apply High Temp-High Strength threadlocker LOCKTITE™ 272, GM P/N 12345493 (Canadian P/N 10953488), or the equivalent, to the propeller shaft to flange bolts. Ensure that there are no gaps in the threadlocker along the length of the filled area of the bolt. Allow the threadlocker to cure approximately ten minutes before installation.

22. Re-install the propeller shaft coupler (1) to the transmission flange.

Tighten
Tighten the propeller shaft coupler-to-transmission flange bolts to 85 N·m(63 lb ft).

23. Re-install the exhaust system.

Tighten
Tighten the catalytic converter nuts to 15 N·m(11 lb ft).

24. Re-install the floor pan brace and bolts to the floor pan.

Tighten
Tighten the floor panel tunnel brace bolts to 25 N·m(18 lb ft).

25. Lower the vehicle.
26. Place the shifter lever in Park.

Limited parts are currently available from GMSPO. Do not order for stock. This condition will only be experienced by a limited number of customers.

For vehicles repaired under warranty, use: