1985 - 1991 Corvette: Service Bulletin: Coated Wheel Weights For Aluminum Wheels
Subject: COATED WHEEL WEIGHTS FOR ALUMINUM WHEELS
Model and Year: 1985-91 MODELS WITH CAST ALUMINUM WHEELS
Source: Chevrolet Service Bulletin
Bulletin Number: 91-35-3E - (06/29/1990)
TO: ALL CHEVROLET DEALERS
THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 89-65-3E, DATED JANUARY 1989. POLYESTER COATED WHEEL WEIGHTS ARE NOW AVAILABLE FROM GMSPO. THE 1990-91 MODEL YEARS HAVE ALSO BEEN ADDED. ALL COPIES OF 89-65-3E SHOULD BE DISCARDED.
Vehicles with cast aluminum wheels use a coated clip on wheel weight. The coating has recently changed from nylon to polyester, giving a more natural appearance that more closely matches the wheel. Coated balance weights are used on both the inboard and outboard rim flanges. They will not discolor, corrode or damage the appearance of the wheel as may have been the case in the past with uncoated clip on weights. These coated weights will fit most GM cast aluminum wheels.
There are two types of coated wheel weights available to fit the GM vehicles (see illustration). Both types of weights are available from GMSPO in 1/4 ounce increments. See usage chart below to determine which type weight is correct for the vehicle.
"MC" Type Weight Used On: 1990-1991 "W" Car 1988-1990 "Y" Car "AW" Type Weight 1989-1991 "L" Car Used On All Other 1991 "B" Car, "U" Van Series Vehicles
1/4 oz. P/N 9591670 P/N 9591669
1/2 oz. 9591584 9591582
3/4 oz. 9591585 9591583
1 1/4 oz. 9591378 9591362
1 1/2 oz. 9591379 9591363
1 3/4 oz. 9591380 9591364
2 oz. 9591381 9591365
2 1/4 oz. 9591382 9591366
2 1/2 oz. 9591383 9591367
3 oz. 9591385 9591369
Parts are currently available from GMSPO.
Dealers should make sure they have a supply of both types weights for balancing GM aluminum wheels.
When installing the coated weights, care must be taken so that the coating does not crack. It is recommended that a Teflon tipped hammer be used, such as 85403 Nicholson Industrial Hammer, their part number CAS 3340551, available through the Charles Strelinger Company, Warren, MI (313-268-4100), or equivalent.
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.
© Copyright General Motors Corporation. All Rights Reserved