Operation CHARM: Car repair manuals for everyone.

A/T - Burned Forward/Direct Clutchs

88chevy06

GMC NUMBER: 88-T-92


GROUP: 7A - Automatic Transmission

DATE: March, 1988

CORPORATE
NUMBER: 877119R
SUBJECT: BURNED FORWARD AND/OR DIRECT CLUTCH PART INFORMATION ON A NEW CENTER SUPPORT BOLT

MODELS: ALL L.D. VEHICLES EQUIPPED WITH THM 400-475 (RPO M40) AUTOMATIC TRANSMISSION
BULLETIN COVERS:

Conditions of a burned forward and/or direct clutch may be caused by a loose center support bolt. A new center support bolt has gone into production to help increase torque retention.

DATE OF PRODUCTION CHANGE:

Beginning December 14, 1987 (Julian Date 348) all THM 400/475 transmissions were built with the new bolt.

SERVICE ACTION:

When ordering an updated support package from GMSPO the new bolt will be included. The bolt must be installed whenever replacement of the center support is required.
If the bolt is not in the center support package, then purchase the new bolt separately. Refer to Service Parts Information.

SERVICE PARTS INFORMATION:

Part No. Part Description

*8629916 THM 400/475 Package-Center
Support and Race Assembly

*8625990 THM 400 Package-Center Support
and Race Assembly

8670757 Bolt-Case to Center Support

*Refer to the service parts list for correct model applications.