CLUNK/SNAPPING FROM FRONT DOOR GLASS-INSTALL DOWN STOP BUMPER

SUBJECT: CLUNK OR SNAPPING NOISE FROM FRONT DOOR GLASS (SERVICE PROCEDURE/ INSTALL DOWN STOP BUMPER)

VEHICLES AFFECTED: 1991 CHEVROLET LUMINA

THIS BULLETIN HAS BEEN REVISED TO CORRECT THE VIN BREAKPOINT FOR PLANT #2.

VEHICLES BUILT BETWEEN THE VIN NUMBERS LISTED BELOW MAY BE AFFECTED:

M9100047 TO M9191541 Plant # 1 * M1100001 TO M1128611 Plant # 2

Condition

1. Clunk noise when rolling front door glass up from full down position. 2. Clunk noise when rolling glass to full down position. 3. Snap noise from door glass. In full up or full down position after a full cycle of the door glass.

Cause

1. No down stop bumper, aluminum backed Butyl tape on bottom of sash channel or square rubber pad at the base of the door.

Correction

1. Remove trim panel. 2. Remove water deflector. 3. Inspect the bottom of the sash channel for aluminum backed Butyl tape. If present remove and clean. Also, remove square shaped rubber bumper at the bottom of the door if present. 4. Remove sheet metal armrest reinforcement. 5. Drill a 11/32 hole as shown in Figure 1. 6. Deburr the hole with a file and paint the sheet metal surface with a zinc rich primer to prevent rust. 7. Install down stop bumper, P/N 20269755 with a blunt Phillips screwdriver, insert screwdriver in the hole in the back side of the bumper. This will assist in pushing the carrot through the hole in the bottom of the door. 8. Cycle the window "to insure proper operation. 9. Reinstall arm rest reinforcement, water deflector, trim panel. 10. Repeat operation for opposite side.

Use the most applicable Labour Operation and Time from the Canadian Labour Time Guide.

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.