Launch Shudder/Vibration on Acceleration (Install New One-Piece Propeller Shaft)
| Subject: | Launch Shudder/Vibration On Acceleration (Install New One-Piece Propeller Shaft) |
| Models: | 1999-2002 Chevrolet and GMC K2500/3500 Extended Cab Long Box and Crew Cab Short Box Pickup Models |
| With Automatic Transmission |
This bulletin is being revised to add model information, remove procedure steps and change parts information. Please discard Corporate Bulletin Number 01-04-17-001A (Section 04 -- Driveline Axle).
Condition
Some customers may comment on a vibration during acceleration from 0-40 km/h (0-25 mph). This may also be referred to as launch shudder. This condition may be more noticeable when the vehicle is carrying cargo or is used for towing.
Correction
A new propeller shaft is available for service to correct this condition. This new propeller shaft is a one-piece design and will replace the current two-piece design.
Install a new one-piece propeller shaft on affected vehicles. Refer to the service procedure and the parts information listed below. Match the affected vehicle with the appropriate propeller shaft. Refer to the usage information below. This fix does not apply to the Chassis/Crew Cab Models (K35943).
- Remove the propeller shaft assembly and the center bearing. Refer to the Propeller Shaft - Two Piece procedure in the Propeller Shaft sub-section of SI2000. For this bulletin, it is not necessary to mark the components for re-assembly.
- Remove the center bearing support bracket from the kick-up crossmember using a cut-off wheel.
- After removal of the center bearing support bracket, grind the rough metal edges smooth that remain on the crossmember.
- Coat the exposed metal surfaces with frame coating using the information found in the applicable Service Manual and GM Refinish Material Booklet #4901M-D-2002 (English) or #4901M-D-F2002 (French).
- Install the new propeller shaft. Refer to the Propeller Shaft Replacement - One Piece in the Propeller Shaft sub-section of SI2000 for installation guidelines and yoke retainer tightening specifications.
Center Bearing Support Bracket
Important: The center bearing support bracket (1) must be removed in order to provide enough clearance for installation of the one-piece propeller shaft. Avoid damaging the crossmember during removal of the center bracket. For proper clearance, no more than 13 mm (½ in) of the bracket may remain on the crossmember after removal.
Parts Information
P/N | Description | Usage |
|---|---|---|
15077431 | Shaft Asm.- Prop | K25953 w/ LQ4, MT1, C6P (99-00 8600# GVW) |
15077434 | Shaft Asm.- Prop | K25953/35953 w/ M74 (Allison Trans) |
15077435 | Shaft Asm.- Prop | K25953 w/ LQ4, MT1 (HD Model 9200# GVW) |
15077436 | Shaft Asm.- Prop | K35953 w/ LQ4, MT1 (11,400# GVW) |
15093466 | Shaft Asm.- Prop | K25743 w/LQ4, MT1 (HD Model 9200# GVW) |
15093467 | Shaft Asm.- Prop | K25743 w/M74 (Allison Trans) |
Parts are currently available from GMSPO.
Warranty Information
For vehicles repaired under warranty, use:
Labor Operation | Description | Labor Time |
|---|---|---|
F1280 | To remove Two-Piece Propshaft and Center Bearing Mount Bracket and Install One-Piece Propshaft | 0.9 hr |
