Ninety-Eight FWD V6-181 3.0L (1985)
Suspension Strut / Shock Absorber: All Technical Service Bulletins
Suspension - Thumping or Clunking Noise From Rear
SUBJECT
REAR SUSPENSION "LOOSE LUMBER" NOISE
NUMBER: 85-T-35
DATE:
June 11, 1985
MODELS/YEARS
1985 NINETY-EIGHT
SECTION:
3D
Some 1985 Ninety-Eight models may experience a "thumping", "clunking" or "loose lumber" noise from the trunk or rear suspension areas when driving
over small bumps (i.e., washboard road surfaces, rough/broken pavement, etc.). This noise may be more noticeable in cold ambient temperatures (less
than 32~ F).
Comments may also be made of a "wheel drop" noise when a rear wheel drops into a pot hole and the strut bottoms out in maximum extended position..
This is a normal condition which will be more noticeable if the rear trim height is above specification.
If a "loose lumber" or "clunk" condition is encountered, first inspect the rear suspension components and fasteners for proper installation and torque
specifications. Check the Electronic Level Control (ELC) system for proper operation. The ELC system is in exhaust mode at curb height. In exhaust
mode, the air dryer retention valve should hold minimum air pressure in the struts. Minimum air pressure calibration was 7-14 psi on early built cars and
20 psi on all others. Feel the strut bag in exhaust mode to determine that minimum air pressure is present. If all suspension components are properly
installed and the ELC system is working properly, the following steps should be taken:
FIGURE 1
A.
NON-SLEEVED LOWER CONTROL ARM BALL JOINT
1.
Inspect both rear lower control arm ball joint date codes. Each ball joint is stamped with a four-digit date code, located on the lower ball joint
cover near the grease fitting. The date code describes the month, day and year the ball joint was manufactured, and may be interpreted as
shown in Figure 1.
2.
Ball joints with date codes 6204 (June 20,1984) and later were produced with a nylon sleeve for noise reduction. Ball joints with date codes
earlier than 6204 should be replaced with service ball joint kit, WDDGM part no. 9769581. Except for date code information, there is no
visible difference between sleeved and non-sleeved ball joints.
B.
UPPER STRUT MOUNT NOISE
Replace both rear upper strut mounts using WDDGM mount kit, part no. 22062510. Each kit contains one replacement mount (identified by a daub
of orange paint) and a complete set of mounting hardware. Two mount kits are required.
The following procedure should be used for strut mount replacement:
1.
To remove the upper strut mount, it is necessary to support the rear lower control arms outboard enough so that coil spring tension does not
load the strut.
2.
Position car on a hoist capable of raising rear of car by supporting rear control arms just inboard of ball joint. A frame contact hoist may be
used by properly lifting the car, then lowering the rear of the car onto low jack stands placed as far outboard as possible under the rear control
