DRIVELINE STOP CLUNK SPECIAL LUBRICANT RELEASED
SUBJECT: DRIVELINE STOP CLUNK (SPECIAL LUBRICANT)
VEHICLES AFFECTED: 1988-91 C1, C2 WITH 4L60 AND 3L80 AUTOMATIC TRANSMISSION
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) 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. 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 propshaft.
SERVICE PARTS INFORMATION
Part Number Description ----------- ---------------------------- 12345879 1 lb. can of special lubricant (should service about 50 vehicles)
General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.
