Suspension - Noise From Rear
89cadillac09Bulletin No. T-89-139
File in Group 30
Number 8
Corp. Ref. No 913401
Date Aug. 1989
SUBJECT: REAR SUSPENSION NOISE (GREASE BALL JOINTS)
MODELS AFFECTED: 1989-1990 DE VILLES AND FLEETWOODS
Some 1989-1990 DeVilles and Fleetwoods may experience a "thump", "clunk", or "pop" noise from the rear suspension or trunk areas when driving over small bumps and around corners (i.e., washboard road surfaces, railroad tracks, etc.). This noise may be more pronounced at low mileage and in hot ambient temperatures (greater than 80~ F) with high humidity. The noise may be reproduced on smooth surfaces by driving the car in "figure eights".
If this condition is encountered, first inspect the rear suspension components and fasteners for proper installation and that they are tightened to torque specifications. Check the Electronic Level Control (ELC) system for proper operation. Ensure that the trunk lid hinges are not contacting the strut towers. Reposition hinge(s) away from strut tower to provide clearance between hinge and tower if contact is evident (paint rubbed through). If all suspension components are properly installed, ELC system is operating correctly, and the trunk hinges are not contacting the strut towers use the following procedure:
1. Grease both rear ball joints and tie rod ends.
2. Jounce car such that the rear ball joints and tie rod ends will move.
3. Re-grease both rear ball joints and tie rod ends.
4. Evaluate car for noise.
If noise is still present (even though it may be reduced), use the following procedure:
1. On the side of the car that the noise is coming from, separate the rear control arm from the knuckle at the ball joint using the removal and installation procedures in Section 3D of the Service Information Manual.
2. Grease the ball joint through zirk fitting while rotating the ball joint stud.
3. Reassemble control arm to knuckle.