Drivetrain - Driveline Stop Clunk

Number:
92-265-7A

Section:
7A

Date:
AUGUST 1992

Corporate Bulletin No.:
964101R

ASE No.:
7A



Subject:
DRIVELINE STOP CLUNK


Model and Year:
1988-91 C1 AND C2 TRUCKS AND 1991-92 CAPRICE WITH 3L80 AND 4L60 AUTOMATIC TRANSMISSION



THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 91-242-7A, DATED MARCH 1991. THE 1991-92 CAPRICE HAS BEEN ADDED. ALL COPIES OF 91-242-7A SHOULD BE DISCARDED.

Normal driveline tension build-up is released following vehicle braking on some 1988-91 C1 and C2 models (with single piece propshafts and automatic transmissions) and 1991-92 "B" Models as driveline clunk when stopping. The tension build-up is the result of the driveshaft splines binding on the transmission slip yoke.

To eliminate stop clunk due to spline-yoke bind, the driveshaft splines should be lubricated with a special lubricant. This bulletin releases a new lubricant that has increased durability over the previously released lubricant.

NOTICE:
This procedure should be applied to 1988-91 C1, C2 vehicles with automatic transmissions and one-piece propshafts only and 1991-92 B Models. When applied to other vehicles, possible transmission lube contamination could result.

SERVICE PROCEDURE:

1. Remove driveshaft.

2. Clean slip yoke and inside of driveshaft spline with solvent and clean cloth.

3. Apply grease (P/N 12345879) to slip yoke spline with a brush or swab, so as to completely cover the entire spline with a light coating of grease.

4. Reinstall driveshaft.

SERVICE PARTS INFORMATION

Part Number Description

12345879 1 lb. can of special lubricant (should service about 50 vehicles)

Parts are currently available from GMSPO.

WARRANTY INFORMATION

For vehicles repaired under warranty use:

Labor Operation:
T7995

Labor Time:
.4 hr

NOTE:
Labor Operation is coded to base vehicle coverage in the warranty system.