DOOR WINDOW DISENGAGEMENT (INSTALL NEW FRT. RUN CHANNEL)

SUBJECT: DOOR WINDOW DISENGAGEMENT FROM CHANNEL (INSTALL NEW FRONT RUN CHANNEL)

VEHICLES AFFECTED: 1990 - 92 "C" COUPES

Some 1990-1992 DeVille and Fleetwood Coupes may exhibit door window disengagement from channel. This may occur due to front run channel and window guide clips damage. A revised front run channel made of stainless steel can now be used to correct this condition using the following procedure:

1. Remove the front door trim panel. Remove front run channel and window from the door. Replace the plastic guide clips on the front and rear of the window (P/N 12337898 front and 20747509 rear). RTV should be applied around the clip snaps to reduce tolerance in the window hole when installed. Ensure that all clips snap together properly when installed.

2. Check the window run channel weatherstrip in the mirror area; replace if split. Lubricate the window sash channel and cam with white-lube.

3. Install a new front run channel with (P/N 25609316 LH or 25609317 RH) and reinstall the window. If a plastic shim was on the old run channel upper attachment from production, it should be transferred to the new part. Lube the new channel with white-lube. Verify proper run channel upper position per Product Service bulletin #90-2-219.

4. Remove the window down stop rubber block from the bottom of the door and operate the window to the full down position. The upper rear edge of the door glass should be at least 1/8" (3mm) above the belt line weatherstrip but must not protrude above the belt line weatherstrip by more than 3/8" (10mm) maximum. The front window guide clip should not be below the end of the new front run channel.

If OK, go to step 5. If window is too low, go to step A. if the window is too high, go to step B.

A. If the window is too LOW when fully open, the regulator tape travel should be shortened by one notch at the motor housing end. Disengage the tape from the four retainer tabs on the plastic motor housing and reposition in a direction that will cause the tape to extend past the last tab by one notch. Go to step 5.

B. If the window is too HIGH when fully open, the regulator tape travel should be lengthened by one notch at the motor housing end. Disengage the tape from the four retainer tabs on the plastic motor housing and reposition in a direction that will cause the tape to now be installed onto three notches. Go to step 5.

5. Reinstall the window down stop rubber block in the door. With the window fully down, the window should make light contact with the block to help stabilize the window when closing the door. If the rubber block is not tall enough, it can be built up using rubber patch material from fuel tank isolation kit, P/N 3523199, or equivalent.

6. Check operation of glass and reinstall the door trim panel.

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.