REAR AUX. SPRING NOISE REPLACE REAR SPRING STOPS W/NEW STYLE

SUBJECT: REAR AUXILIARY SPRING NOISE

MODELS: 1988-90 C2, C3, K3 TRUCKS (MODELS C20903, C/K30903 & R05 (DUAL REAR WHEELS) AND C/K30953 & R05) EQUIPPED WITH AUXILIARY REAR SPRINGS

THIS BULLETIN CANCELS AND REPLACES GMC TRUCK SERVICE BULLETIN 90-3D-90(A) DATED OCTOBER, 1990 TO RESTRICT INVOLVED TRUCKS TO MODELS C20903, C/K30903 & R05 AND C/K30953 & R05. ALL COPIES OF 90-3D-90(A) SHOULD BE DISCARDED.

Some 1988-90 C2, C3 and K3 trucks equipped with auxiliary rear springs may experience a noise from the rear spring area. This noise may be described as a slap sound and is caused when the auxiliary, or second stage springs, contact the spring stops.

This condition can be repaired by replacing the existing spring stops and insulators with revised one piece spring stops. These revised spring stops feature insulators which are molded directly to the metal stop (Figure 1).

INVOLVED VEHICLES:

All 1988-90 C2, C3 & K3 vehicles (models C20903, C/K30903 & R05 (dual rear wheels) and C/K30953 & R05) equipped with auxiliary rear springs. These involved vehicles can be identified from other C3 & K3 models by examining the rear auxiliary spring stops (Figures 2 & 3). If the design and bolt pattern do not match those shown in Figures 2 & 3 the truck is not involved and the part numbers listed cannot be installed on the truck. Vehicles built after the VIN breakpoints listed below are equipped with the revised stops.

Ft. Wayne (Z) - No Vehicles Involved

Oshawa (1) - GMC L1 551872 Chevrolet L1 229961

Pontiac E (E) - GMC LE539500 Chevrolet LE219187

SERVICE PARTS INFORMATION

Part Number Description Quantity -------- ------------------------- ---------- 15654886 Rear Spring Stop, Front 2 15654887 Rear Spring Stop, Rear 2

Parts are currently available from GMSPO.

WARRANTY INFORMATION

For vehicles repaired under warranty use:

Labor Operation Number: T7051 Labor Time: .6 Hr

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.