For 1990-2009 cars

# INFO. ON PREVEN. OF DAMAGE TO POLYCAST WHEELS DUR. BALANCING

#### SUBJECT: INFORMATION ABOUT THE PREVENTION OF DAMAGE TO POLYCAST WHEELS DURING BALANCING

MODEL/YEARS: 1992-93 ACHIEVA

Polycast wheels on some 1992-93 Achieva models may incur cosmetic damage during wheel balancing on some off-car wheel balancers.

During tightening, the balancer's pressure cup may imprint into the polycast material on the front face of the wheel.

Use pressure cups that are protected with rubber, plastic or other nonmetallic materials where contact is made with the wheel. Make sure pressure cup is free from dirt, grease or gouges. Most wheel balancers now offer this type of protected pressure cups, which are also recommended for aluminum wheels.

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

DO NOT OVERTIGHTEN. If the balancer has a "wing nut" design (see the illustration below), hand tight is sufficient.

After balancing, a circular imprint from the protected pressure cup may exist around the wheel's bolt circle area. This is temporary and will "relax" out of the polycast material within hours.

The above procedure will allow accurate balancing with the conventional use of the back cone.

#### Important: This polycast wheel requires "AW" series balance weights on the outboard side, and standard weights for steel wheels on the inboard side.

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.