Each shock absorber can be tested by bouncing the corner of the vehicle until maximum up and down movement is obtained. Let go of the vehicle. It should stop bouncing in 1-2 bounces. If not, the shock absorber should be inspected for damage and possibly replaced.
Shock Absorber Mountings
Check the shock absorber mountings for worn or defective grommets, loose mounting nuts, interference or missing bump stops. If no apparent defects are noted, continue testing.Fluid Leaks
Disconnect each shock absorber lower mount and pull down on the unit until it is fully extended. Inspect for leaks in the seal area. Shock absorber fluid is very thin and has a characteristic odor and dark brown color. Do not confuse the glossy paint on some shock absorbers with leaking fluid. A slight trace of fluid is a normal condition; shock absorbers are designed to seep a certain amount of fluid past the seals for lubrication. If you are in doubt as to whether the fluid is coming from the shock absorber itself or from some other source, wipe the seal area clean and manually operate the shock absorber, using the following procedure. Fluid will appear if the unit is leaking.
It may be necessary to fabricate a holding fixture for certain types of shock absorbers.
- Grip the lower end of the shock absorber. Pull down (rebound stroke) and then push up (compression stroke). Compare the rebound resistance of both shock absorbers and compare the compression resistance. Usually, any shock absorber showing a noticeable difference will be the one at fault.
- If the shock absorber has internal noises, extend it fully, then exert an extra pull. If a small additional movement is felt, this usually means a loose piston, and the shock absorber should be replaced. Other noises which indicate the need for replacement are a squeal after a full stroke in both directions, a clicking noise on fast reverse, and a lag at reversal near mid-stroke.
REMOVAL & INSTALLATION
See Figures 1, 2, 3 and 4
It is recommended that shock absorbers be replaced in pairs, to maintain uniform handling.
- Remove the upper attaching nut, washer, and insulator. Access is through the trunk on sedans and convertibles, or side panel trim covers on hatchbacks. The studs in sedans and convertibles are concealed by rubber caps.
- Raise and safely support the rear of the car, including the rear axle.
- Compress the shock absorber to clear the upper tower. Remove the lower nut and washer, then remove the shock absorber.
- Purge the new shock absorber of air and compress it.
Purge a new shock absorber of air by repeatedly extending it in its normal position and compressing it while inverted.
- Place the lower mounting eye over the lower stud, then install the washer and a new locking nut. Do not tighten the nut yet.
- Place the inner washer and insulator on the upper stud. Extend the shock absorber and install the stud through the upper mounting hole.
- Torque the lower mounting nut to 40-55 ft. lbs. (54-75 Nm) for 1979-81 cars, or 55-70 ft. lbs. (75-95 Nm) for 1982-88 cars. If equipped with a self-wrenching nut, be sure that the wrenching tab seats against the outboard leg of the axle bracket.
- Remove the supports and lower the car.
- Install the outer insulator and washer on the upper stud, and install a new nut. Tighten to 14-26 ft. lbs. (19-35 Nm) for 1979-81 cars, 24-26 ft. lbs. (33-35 Nm) for 1982 cars, 17-26 ft. lbs. (23-35 Nm) for 1983-86 cars, or 19-27 ft. lbs. (26-37 Nm) for 1987-88 cars.
- Install the trim panel on hatchbacks, or the rubber cap on sedans and convertibles.