DIESEL RATTLE/KNOCKING NOISE NEW FLYWHEEL INFORMATION

A LOUD RATTLE OR KNOCKING NOISE COMING FROM THE REAR OF THE DIESEL ENGINE MAY BE CAUSED BY THE FLYWHEEL CASTING AND PLATE NOT BEING RIVETED TIGHTLY. THE STAINLESS STEEL RIVETS USED TO FASTEN THE CASTING AND PLATE TOGETHER MAY LOOSEN AFTER SOME MILEAGE HAS ACCUMULATED AND THUS, CAUSE THE RATTLE OR KNOCKING NOISE CONDITION. BEGINNING APRIL 21, 1982 A NEW FLYWHEEL ASSEMBLY WAS RELEASED INTO PRODUCTION. THE RIVETS USED IN THE NEW FLYWHEEL ASSEMBLY ARE MADE OF COLD ROLLED STEEL AND ARE INSTALLED FROM THE OPPOSITE DIRECTION. TO DETERMINE IF THE FLYWHEEL IS THE CAUSE OF THE RATTLE OR KNOCKING NOISE, REMOVE THE FLYWHEEL COVER AND LISTEN TO SEE IF THE NOISE IS LOUDER. IF IT IS, REPLACE THE FLYWHEEL ASSEMBLY WITH PART NO. 22520094

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.