SERPENTINE BELT NOISE-REMOVE IDLER PULLEY-NEW BELT P/N

VEHICLES AFFECTED: 1987 S/T MODELS WITH 2.8L (VIN CODE R) ENGINES, N40 POWER STEERING, AND WITHOUT AIR CONDITIONING A/C)

Some 1987 S/T trucks with 2.BL V6 engines, N40 power steering, and without A/C may experience a "chirp" noise from the serpentine belt. This noise may be caused by high belt load conditions.

If this condition is encountered, it can be repaired by removing and discarding the belt idler pulley and replacing the belt with P/N 10069211 (See Figure No. 1). Use the procedures in Section 6Bl - Engine Cooling for belt replacement.

This change was made in production beginning with the following VIN breakpoints:

Pontiac Chevrolet H0124149 GMC H0506673

Moraine Chevrolet H2146612 GMC H2509701

Shreveport Chevrolet H8142478 GMC H8512179

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.