TIMING BELT ADJUSTMENT UPDATED SERVICE PROCEDURE

VEHICLES AFFECTED: 1982 - 86 1.8L OHC Engine (LH8-VIN Code O and LA5 - VIN Code J)

A new 20mm wide timing belt, P/N 90234902 has been released for production and service on 1982 through 1986 1.8L OHC enngines.

When a new timing belt is installed and tensioned, the engine must be turned over (without starting) approximately 10 revolutions. As the new belt takes a set position, a substantial tension loss will occur, and the timing belt must then be retensioned.

When a new 20mm wide timing belt is installed or an existing 19mm wide timing belt is retensioned, it must be tensioned to within the band (between two arrows on perimeter of gauge dial face identified by 1.8L OHC) as shown in figure 1. The band represents 15ON (30 lbs.) on a cold engine. The timing belt tension gauge, J-26486-A was an essential tool included originally in the T-1000 tool package. This same tool was reworked and released for the 1.8L OHC engine. Because of the importance of correct timing belt tensioning, it is imperative all Dealerships use the gauge that has accurate calibrations.

NOTICE: ALL TENSION ADJUSTMENTS ARE TO BE MADE ON A COLD ENGINE. THIS IS A PROCEDURAL CHANGE FROM PREVIOUS BULLETINS AND SECTION 6A1-12, STEP 5, OF THE 1986 PONTIAC SUNBIRD SERVICE MANUAL.

Use applicable labour time and labour operation for this operation.

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.