Aluminum Wheels - Cosmetic Damage During Balancing

Number: 93-197-3E
Section: 3E
Date: MAY 1993
Corporate Bulletin No.: 393502
ASE No.: A4

Subject:
INFORMATION ON COSMETIC DAMAGE TO ALUMINUM WHEELS DURING BALANCING

Model and Year:
1988-93 C1, K1, G, E/J, L/M, P, S/T, R/V
1990-93 LUMINA APV

Some aluminum wheels on GM models may incur cosmetic damage during balancing if proper care and procedures are not used. All aluminum wheels have a clearcoat 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 clearcoat on the face of the wheel. Like any other clearcoat 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 nonmetallic 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.