For 1990-2009 cars

# INFO. ON COSMETIC DAMAGE TO ALUMINUM WHEELS DURING BALANC.

#### SUBJECT: INFORMATION ON COSMETIC DAMAGE TO ALUMINUM WHEELS DURING BALANCING

#### MODELS AFFECTED: 1988-1993 CADILLACS WITH ALUMINUM WHEELS

Some 1988-1993 Cadillacs with aluminum wheels may incur cosmetic damage during balancing if proper care and procedures are not used. All aluminum wheels have a clear coat paint on them that must be cared for like any other painted surface.

Some off-car wheel balancer retaining cups used to clamp the wheel to the balancer may put a circular mark into the clear coat on the face of the wheel. Like any other clear coat damage this may be difficult to remove or repair, depending on severity.

ALWAYS use balancer retainer cups that are protected with rubber, plastic, or other non-metallic materials where contact is made with the wheel. Make sure the retainer cup is free from dirt, grease, and gouges. Most wheel balancers now offer this type of protected retainer.

DO NOT allow the retainer cup to rotate against the wheel's surface when tightening the wheel to the balancer.

DO NOT OVERTIGHTEN. Most balancers use a large "wing nut" design to clamp the retainer against the wheel. Hand tight is sufficient.

This procedure will allow accurate balancing using the conventional back cone method.

#### IMPORTANT: Coated balance weights must be used on aluminum wheels to prevent damage to the rim flange.

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.