WIND NOISE (INFORMATIONAL)

SUBJECT: WINDNOISE (INFORMATIONAL)

VEHICLES AFFECTED: 1993 "B" CAR

THIS BULLETIN SUPERSEDES AND REPLACES CORPORATE BULLETIN REFERENCE NUMBER 331039.** THIS BULLETIN IS BEING REVISED TO CHANGE CANADIAN BULLETIN NUMBER FROM 93-10-239 TO 93-10-255.

Customer comments regarding wind noise may be addressed by using the procedures on the individual items listed in this bulletin. Proper diagnosis may be made with a variety of tools and methods including stethoscopes, dust guns, sonic instruments, visual inspections, dollar bill method etc. It is important to remember that wind noise can best be described as air leaking from inside of the vehicle outward while traveling at highway speeds. Turbulence or wind rush is best described as air passing over and around body openings and moldings.

Prior to any repairs, the front and rear door auxiliary weatherstrips and door primary opening weatherstrips should be visually inspected for proper gaps, fits, weatherstrip contact, and sealing. The vehicle should also be road tested to determine location and degree of wind noise/turbulence on the vehicle.

The recommended materials to be used with the following procedures are:

American Sure Seal Bedding Compound P/N CGB American Sure Seal Strip Caulk (Black) P/N BSC GM Urethane Adhesive Kit P/N 12345633 (NAES)/993110 (GMCL) GM Goodwrench RTV Silicone Rubber P/N 12345336 GM Goodwrench RTV Silicone Rubber Sealant P/N 12345739 Kent Auto Bedding and Glazing Compound P/N 10255 Kent Tracing Powder P/N 20065 3M Auto Bedding + Glazing P/N 08509 3M Ultropro Auto Body Sealant (Clear) P/N 08302 3M Strip Caulk P/N 08578 3M Leak Tracing Powder P/N 08951 3M Silencer Strips P/N 08585

3M and American Sure Seal Inc. can be purchased locally.

Kent Products distribution can be obtained by calling 1-800-654-6333.

*We believe these sources and their product 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 from these firms or for any such items which may be available from other sources."

CORRECTIONS:

----------- I. Windshield upper reveal molding gaps to the roof of 2mm or less, follow procedure A (See Figure 1, top illustration, for gap). If gap is larger than 2mm follow Procedure B.

Procedure: A ------------ 1. With 1/2 inch masking tape, tape the upper reveal molding all the way across the roof following the rear most edge of the reveal molding. Tape the roof at the rear edge of the molding all the way across the car.

2. Using GM Goodwrench RTV Silicone Rubber Sealer, P/N 12345739, and the nozzle from the package, fill the gap between the molding and the roof.

3. Remove tape and clean any excess sealer on the molding and the body with adhesive cleaner.

For vehicles repaired under warranty use:

Labor Time: 0.3 Hr.

PROCEDURE B

NOTE: This procedure may require a new molding depending on difficulty of removal. Windshield upper reveal molding, P/N 16616066.

Windshield upper reveal molding gaps to the roof may be corrected by following the procedure listed below.

1. Loosen and remove (partially) both RH and LH auxiliary weatherstrips.

2. Remove both windshield side reveal moldings.

3. Grasp the windshield upper reveal molding end and rotate forward while removing from cavity.

4. Remove the foam tape from the molding if present from the back side of the molding.

5. Trim the lower lip off the reveal molding as shown in (Figure #1).

6. Dry fit the molding to the opening.

7. Remove adhesive from cavity if necessary.

8. Apply urethane, P/N 12345633, into the cavity up to the bottom side of the windshield.

9. Install molding.

10. Tape the molding to the body using masking tape.

11. Allow urethane to cure at room temperature over night before removing tape.

12. Remove any excess squeeze out of urethane from the glass and the body after tape is removed.

For vehicles repaired under warranty use:

Labor Time: 0.7 Hr.

II. Wind rush due to gap at windshield side reveal molding to glass, left and/or right side.

1. Remove auxiliary weatherstrip to access the windshield side reveal molding retaining screws.

2. Remove the retaining screws and the molding.

3. Holding the windshield side reveal molding in position, flush the molding to the glass. Determine how much elongation of the screw holes in the molding is necessary to position the molding flush to the glass.

4. Using a small rattail file, elongate the retaining holes in the direction and length needed to position the molding flush to the glass.

5. On the under side of the reveal molding run a bead of RTV or equivalent across width of molding at the lower retaining hole to fill the void between the glass and the inside surface of the windshield side reveal. (See Figure 2, Section A-A). Sealing this area will stop a tunneling effect up the molding.

6. Put a light film of oil on the A-pillar at the lower retaining hole to facilitate any future serviceability for removing the molding.

7. Reinstall the windshield side reveal molding and retaining screws per Section 10-2 of the Service Manual.

8. Using strip caulk, fill the cavity at the top of the windshield side reveal molding to the upper windshield reveal molding.

IMPORTANT: Be careful not to trap the primary seal under the auxiliary seal when reinstalling the auxiliary seal.

For vehicles repaired under warranty use:

Labor Operation:

Labor Time: 0.3 Hr 0.2 Hr. For Other Side

III. Wind noise due to air leak at primary weatherstrip to door frame.

1. Adjust the door inboard to obtain necessary contact to the door frame.

IV. Windshield side reveal molding gaps to door.

Adjust the door inboard so there is slight contact of the door frame along the A-pillar to the windshield side reveal molding.

V. Front edge of the front door may be outboard slightly of the front fender.

Adjust the front edge of the front door inboard of the front fender. Flush to 1.5 mm inboard. (See Figure 3.)

NOTE: In rare instances it may be necessary to adjust the front fender outboard to obtain a proper fit.

VI. Front edge of the rear door may be outboard slightly of the front door.

Adjust the front edge of the rear door inboard of the front door. Flush to 1.5 mm inboard (See Figure 3.)

For vehicles repaired under warranty use:

Door Assembly Align:

Labor Operation: Labor Time: --------------- ---------- B4000 Right Front 0.6 Hr. B4001 Left Front 0.6 Hr. B4400 Right Rear 0.3 Hr. B4401 Left Rear 0.3 Hr.

VII. Wind rush due to front door window belt molding gap to front door window reveal molding. Gap between the two moldings can be seen right behind the mirror.

1. Loosen the front and rear screws of the front door belt reveal molding (See Figure 4.)

2. Tap the belt molding forward to close the gap to the front reveal.

3. Retorque the screws.

For vehicles repaired under warranty use:

Labour Operation: B7840 Right B7841 Left

Labour Time: 0.2 Hr. Per Door

VIII. Wind noise at front door window run channel to door frame.

1. Lower door glass.

2. Remove the window run channel from the retainer in the header of the door frame by pulling down and outboard on the run channel.

3. Using bedding and glazing compound, run a 5 mm bead around the inboard edge of the retainer (See Figure 5, Section A-A).

4. Using bedding and glazing compound, fill the two cavities in the upper rear corner of the door frame (See Figure 5, View A).

5. Spray window run channel with glass cleaner, for ease of installation.

6. Reinstall the window run channel, using a plastic trim stick to ensure that the run channel is fully seated in the retainer (See Figure 5, View C).

IX. Wind noise at rear door window run channel to door frame.

1. Lower the door glass.

2. Remove the front, top and rear portion of the run channel from the retainer from the door frame by pulling down and outboard on the run channel.

3. Using bedding and glazing compound, run a 5 mm bead around entire inboard edge of the retainer (See Figure 5, Section A-A).

4. Using bedding and glazing compound, fill the cavities in the bracket area of the upper front corner of the door header and at the top of the division post. (See Figure 5, View B).

5. Spray the window run channel with glass cleaner for ease of installation.

6. Reinstall the window run channel using a plastic trim stick to insure that the run channel is fully seated in the retainer (See Figure 5, View C).

For vehicles repaired under warranty use:

Labor Time: 0.3 H 0.2 Hr. Each Additional Door

CAUTION:

APPROVED SAFETY GLASSES AND GLOVES SHOULD BE WORN WHEN PERFORMING THIS PROCEDURE TO REDUCE THE CHANCE OF PERSONAL INJURY.

BUICK ROADMASTER ONLY -

X. Wind noise at rear door stationary glass seal to door frame.

1. Remove the rear door stationary glass per Section 10 of the Service Manual.

2. Starting at the top of the division post and continuing rearward to the bottom of the stationary glass opening, apply a bead of bedding and glazing compound to the inboard edge of the retainer

3. Fill the two cavities at the lower corner of the stationary glass channel with strip caulk sealer

4. Reinstall stationary glass.

NOTE: When reinstalling stationary glass, care should be taken to ensure that the stationary glass seal is parallel with the belt line molding. The seal flap around the perimeter of the stationary glass must be outboard of the reveal molding.

For vehicles repaired under warranty use:

Labor Operation: C0400 Right C0401 Left

Labor Time: 1.0 Hr. Per Door

BUICK ROADMASTER ONLY -

XI. Road noise from lower rocker area.

Road noise from the lower rocker area may be reduced by removing the outer sill plate and covering the three, 3/4 inch holes with 3M silencer strips. The rear door is similar but only has two holes to cover under the sill plate.

For vehicles repaired under warranty use:

Labor Time: 0.7 Hr.

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.