ROAD NOISE IN PASSENGER COMPARTMENT

SUBJECT: ROAD NOISE IN PASSENGER COMPARTMENT (INSTALL DAMPENING PACKAGE)

VEHICLES AFFECTED: 1989-90 C

Some 1989-1990 DeVilles and Fleetwood Sedans may experience road noise emitting from the rear seat or rear sail panel areas on coarse road surfaces (i.e., worn or stud damaged concrete). This sounds very similar to wheel bearing noise. Follow the procedure below before replacing the hub and bearing assembly.

To repair this condition install dampening package, P/N 25553218 on top of the left and right rear strut towers (inside the rear compartment area) using the following procedure:

1. Remove plastic speaker enclosure from rear shelf, if equipped, and discard. If equipped with Bose speakers, speaker enclosure must be trimmed to provide clearance.

IMPORTANT: Additional trim removal is not necessary.

2. Install one stud extender to the rearmost strut mount stud. Do not remove existing strut mount nuts. Torque to 12-15 N-m.

3. Install left and right dampener masses to the top of the rear shock towers. (Dampeners are marked LH for left and RH for right.)

4. Install washers and M-14 nuts and torque to 20 N-m.

IMPORTANT: After installation check driver's door label and verify that GVWR does not exceed 2141 kg (4720 lbs.) total. If GVWR exceeds 2141 kg (4720 lbs.) total, it will be necessary to install aluminum bumper reinforcements, front and rear, to maintain GVWR specifications. Refer to Figure 1.

25529356 - Front Bumper Reinforcement, Upper 25529347 - Front Bumper Reinforcement, Lower 25529350 - Front Bumper Reinforcement, Outer RH 25529351 - Front Bumper Reinforcement, Outer LH 25529331 - Rear Bumper Reinforcement, Impact Bar 25529328 - Rear Bumper Reinforcement, Outer LH 25529329 - Rear Bumper Reinforcement, Outer RH

Refer to Section 2B in the 1989 DeVille/Fleetwood Service Information Manual.

For warranty purposes use 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.