GM Service Manual Online
For 1990-2009 cars only

OVERRUN GEAR RATTLE OR VIBRATION DURING DECELERATION

Model and Year: 1985 S/T MODELS WITH MANUAL TRANSMISSIONS AND 2.5L (LN8) ENGINES

TO: ALL CHEVROLET DEALERS

A transmission gear rattle or vibration condition noticeable during deceleration on some 1985 S/T models with the 2.5L (LN8) engine may be reduced by replacement of the clutch driven disc with a revised clutch driven disc, P/N 15550410.

Engines equipped with the revised disc were used in production beginning with the following VIN:

Pontiac - F0201638

Shreveport - F8Z47683

Moraine - F2238716

This disc will also be used on the 2.8L V6 engine beginning with the 1986 model year.

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.