A/T - Second Gear Vibration, 40-55 MPH

Group Ref.: Transmission

Bulletin No.: 377135A

Date: March, 1994

SUBJECT:
SECOND GEAR VIBRATION BETWEEN 40-55 MPH - MEDIUM TO HEAVY THROTTLE (REPLACE FOURTH CLUTCH HUB AND SHAFT ASSEMBLY)

MODELS:
1994 BUICK SKYLARK
1994 CHEVROLET BERETTA AND CORSICA
1994 OLDSMOBILE ACHIEVA
1994 PONTIAC GRAND AM EQUIPPED WITH 3.1L ENGINE (VIN M - RPO L82)

TRANSAXLE APPLICATIONS:
HYDRA-MATIC 4T60-E (RPO M13) (BUILT ON OR BEFORE SEPTEMBER 24, 1993, JULIAN DATE 264)

TRANSAXLE MODELS:
4WBW, 4WSW

THIS BULLETIN IS BEING REVISED TO CHANGE THE REPAIR COMPONENT NAME AND WARRANTY INFORMATION. PLEASE DISCARD BULLETIN 377135.





CONDITION:
(Figure 1) Some owners may experience a transaxle vibration while in second gear between 40-55 mph, (medium to heavy throttle). This vibration will be more noticeable at higher engine speeds, for example during a 4-2 downshift.





CAUSE:
(Figure 2) This condition may be due to an off center bore in the Fourth Clutch Hub and Shaft Assembly that houses the Fourth Clutch Bearing Assembly. The off center bore may cause the transaxle to vibrate in second gear at high engine speeds.

CORRECTION:
(Figure 2) A new Fourth Clutch Hub and Shaft Assembly has been released. The new Fourth Clutch Hub and Shaft Assembly can be identified by a purple (ink) stripe around its shaft.





SERVICE PARTS INFORMATION:

Parts are currently available from GMSPO.

WARRANTY INFORMATION:

For vehicles repaired under warranty, use:

Labor Operation: K7528

Labor Time: Use the published labor operation time.