Some 1987-1988 Rivieras built after 1987 VIN breakpoint 441555 and prior to 1988 VIN breakpoint 402080 may experience a windnoise condition at the mirror section of the front door windows. This may be caused by the omission of thumb grade (strip caulk) sealer at the step where the glass run channel weatherstrip retainer and door come together. To repair this condition, use the following procedure:
1. With the window in the down position remove 8 to 10 inches of the glass run channel weatherstrip from the weatherstrip retainer, as shown in Figure 1.
2. At the end of the weatherstrip retainer there is a step where the door and retainer meet. Add thumb grade (strip-caulk) sealer, 3M Part Number 08578 or equivalent, as shown in Figure 2, views B and C.
3. Reinstall the glass run channel weatherstrip to the cavity of the weatherstrip retainer. IMPORTANT: Be sure that the weatherstrip is correctly seated as shown in Figure 1, Section B-B.
For warranty purposes, use Labor Operation T6256 at .3 hour.
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.