GM Service Manual Online
For 1990-2009 cars only

DRIVELINE TORSIONAL VIBRATION LOW RPMS-REVISED CLUTCH P/N

MODELS: 1984-1987 S/T TRUCKS WITH MANUAL TRANSMISSIONS

THIS BULLETIN CANCELS AND SUPERSEDES TRUCK SERVICE BULLETIN 86-B-22 DATED DECEMBER, 1985, ALL COPIES OF WHICH SHOULD BE DESTROYED.

Some 1984-87 S/T trucks that experience driveline torsional vibration (noticeable at low engine RPM) may be repaired by installing a revised clutch plate, which incorporates a longer dampener travel to remove vibration.

P/N 15608690 Plate Assembly 2.5L (LN8) P/N 15608691 Plate Assembly 2.8L (LL2)

The above parts will be incorporated into production with the start of 1988 model year trucks.

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.