Aluminum Wheels - Discoloration or Surface Degradation
Bulletin 86-3-10Date July, '86
Ref. No. 86-145-3
SUBJECT: CLEAR COATING OF ALUMINUM WHEELS
MODELS AFFECTED: ALL MODELS WITH ALUMINUM WHEELS
NOTICE: This procedure is an improvement over that in Service Bulletin 85-3-17, dated March, 1985. Use this new procedure whenever possible.
The purpose of this service bulletin is to assist dealerships in repairing the discoloration of surface degradation that has been experienced on certain style cast aluminum wheels.
SERVICE REPAIR PROCEDURE:
WHEEL REMOVAL
Mark Wheel and tire for position on car. Remove wheel and tire assembly from car. 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, oil with solvent cleaner.
ACCENT COLOR PREPARATION
Sand over painted areas, that will not require recoloring, with 400 grit (wet or dry) to promote adhesion of clear coat.
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.
- 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 recommendations.
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.
RECOATING PROCEDURE
1. Clean surface of contaminants.
2. Spray wheel with Amchem #33, let soak from 1 to 3 minutes; then rinse with water and blow dry.
3. Spray wheel with Amchem #1001, let soak for 1 to 3 minutes; then rinse with water and blow dry.
4. Finish with Ditzler Delclear Acrylic Urethane and Ditzler Ultra Urethane Additive (three coats).
1st coat - Light mist coat, let flash
2nd coat - Light, let flash
3rd coat - Heavy double wet coat
5. Let dry for 24 hours -- or, flash for 30 minutes. Force dry at 140~ for 30 minutes, and allow to cool for 30 minutes before mounting.
WHEEL INSTALLATION
1. Rebalance tire/wheel assemblies by replacing the original balance weights with nylon coated weights.
2. Install tire/wheel assembly onto car.
REQUIRED MATERIALS
1. Amchem Alumi Prep #33 - Stock #DX533 (or equivalent) - Cleaning and conditioning chemical for aluminum.
2. Amchem Alodine #1001 - Stock #DX501 - Coating chemical for aluminum.
3. Ditzler Delclear Acrylic Urethane Clear - Stock #DAU-75.
4. Ditzler Delthane Ultra-Urethane Additive - Stock #DXR-80.
(All above available from PPG Industries, Inc./Ditzler Jobbers.)
5. Nylon coated Weights - These are available from GMWDD in 1/4 ounce increments ranging from 1/4 ounce to 3 ounces, Part Number 9591358 through 9591367, inclusively.
WARRANTY INFORMATION
LABOR OPERATION NUMBER: T1170
LABOR TIME: 1.7 hours
ADD: Each additional wheel 1.5 hours
TROUBLE CODE: 92
MATERIAL ALLOWANCE: $3.75 per wheel
"We believe this source and their products to be reliable. There may be additional manufacturers of such products. 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."