CLEAR COAT ON ALUMINUM WHEELS REPAIR PROCEDURE OUTLINED

MODELS: ALL S/T AND C/K MODELS EQUIPPED WITH ALUMINUM WHEELS

THIS BULLETIN CANCELS AND SUPERSEDES 85-B-60 (MARCH, 1985), ALL COPIES OF WHICH SHOULD BE DESTROYED.

The purpose of this service bulletin is to assist dealerships in repairing the discoloration or surfaoe degradation that has been experienced on certain style cast aluminum wheels.

SERVICE REPAIR PROCEDURE

I. Wheel Removal

Mark wheel and tire for position on vehicle. Remove wheel and tire assembly from vehicle. Mask off tire prior to painting. Mark location of outboard weights and remove.

Wash wheel inside and out with water base all purpose cleaner. Remove grease and oil with solvent cleaner.

II. Surface Preparation

Note: It is not necessary to remove tire from wheel assembly to perform this procedure, however, if for any reason the tire is removed, its position to the wheel must be marked using the valve stem as an index. When remounting, tire should be returned to original position on wheel.

A. Surface Damage, Clear Coat Damage

1. Mount wheel on brake lathe and spin slowly.

a. Sand wheel with backing block or pad by holding abrasive flat to surface of wheel and moving slowly back and forth from center to outer edge to remove imperfections.

1) Sand with 80 grit* 2) Sand with 150 grit 3) Sand with 240 grit

*Never use abrasive coarser than 80 grit

B. Slight Clear Coat Damage On Unpainted Wheels.

1. Apply chemical stripper - allow stripper to penetrate coating.

Special Note - Use small 1/4" detail brush dipped in stripper to apply material around perimeter and spoke-like areas.

2. Remove stripper - follow manufacturers recommmendations.

3. Sand wheel with 240 grit while rotating wheel on a slow spinning brake lathe or by mounting on vehicle and spinning by hand. This step is to restore the machined appearance and to promote adhesion.

WARNING:

Do not use vehicle power to rotate wheel while sanding to avoid serious personal injury.

III.Recoating Procedure

A. Clean surface of contaminants.

B. Spray wheel with Amchem #33 or equivalent, let soak from 1 to 3 minutes, then rinse with water and blow dry.

C. Spray wheel with Amchem #1001 or equivalent, let soak from 1 to 3 minutes, then rinse with water and blow dry.

D. Finish with Ditzler Delclear Acrylic Urethane and Ditzler Utra Urethane additive or equivalent. Three coats.

lstCoat - Light mist coat, let flash 2nd Coat - Light, let flash 3rd Coat - Heavy double wet coat

E. Let dry for 24 hours - or flash for 30 minutes, force dry at 140 degrees for 30 minutes, and allow to cool for 30 minutes before mounting.

IV. Wheel Istallation

A. Rebalance tire/wheel assemblies by replacing the original balance weights with nylon-coated weights.

B. Install tire/wheel assembly onto vehicle.

Required Materials

Amchem Alumi Prep #33 - stock #DX533 or equivalent - cleaning and conditioning chemical for aluminum.

Amchem Alodine #1001 - stock #DX50'r or equivalent - coating chemical for aluminum.

Ditzler Delclear Acrylic Urethane Clear - stock #DAU-75 or equivalent.

Ditzler Delthane Ultra-Urethane Additive - stock #DXR-80 or equivalent.

Nylon-coated weights-One possible source for these parts is WDDGM in 1/4 ounce increments ranging from 1/4 ounce to 3 ounces, P/N 9591358 through 9591367, inclusively.

Labor Operation Number: T1170 Labor Time: 1.7 Hours

Add: Each additional wheel - 1.5 hours.

Material Allowance - $3.75 per wheel

We believe these sources and their equipment to be reliable. There may be additional manufacturers of such equipment. General Motors does not endorse, indicate any preference for, or assume any responsibility for the products or equipment from these firms or for any such items which may be available from other sources.

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.