How to Inspect Shock Absorbers

2013-1-8 15:15:04


1.Road test the vehicle for signs of shock absorber malfunction. Check for excessive bouncing after hitting bumps--this signals that the shock absorbers are not damping (restricting) the action of the springs. Substandard braking and poor handling in turns may be an indication that the tires are not making proper contact with the road. If the vehicle's front end dips when braking, or the vehicle "squats" during acceleration, the shock absorbers may not be functioning properly upon compression.

2.Park the vehicle and shut off its engine. Rock all four corners of the vehicle separately by pressing down on the ends of the bumpers. Rock the vehicle at each spot several times and then release it. Observe how many times the vehicle bounces on its own. If it bounces more than two times before returning to its original position, the shock absorber is not damping the spring action properly and may require replacement.

3.Inspect tires for uneven wear and "cupping" (shallow patches of tread that look as if they have been carved out). This is an indication that the vehicle has been bouncing excessively and that patches of tread have been scuffed away as they hit the pavement.

4.Measure the distance between the top of each tire and the center of the outer wheel well edge. If one or more measurements are shorter than the others, the spring may be broken at that location. Since springs and shock absorbers work in conjunction with each other, make sure to also look at the springs when you are checking the shock absorbers.

5.Release the initial tension, or "crack" the lug nuts (just enough until they turn easily) on each wheel before you raise that corner of the vehicle. Lift the vehicle one wheel at a time, safely supporting the chassis on jack stands. Remove the lug nuts and wheel and set them aside.

6.Visually inspect the spring first, using your droplight to illuminate its full circumference. Wipe any oil or dirt from the spring. Check for cracks and scoring, and any other signs of wear. If any spring requires replacement be sure to replace them in pairs, either in the front or in the back.

7.Visually inspect the shock absorber next. Check the rod extending from the top of the shock absorber to make sure it is not bent or broken. Also check the rod for pitting or scoring, which can eventually damage the shock absorber's oil seal. Check the dust shield at the top of the shock absorber for dents and cracks that could lead to rod damage. Check for loose or missing bushings, and loose or broken mounts. Also check for oil leaks. Wipe any oil and dirt from the shock absorber, and check for cracks and oil seeping from the upper seal. The presence of oil is not always a sign that the shock absorber is leaking. The oil may have splashed onto the shock absorber from another part of the vehicle. Be sure to check the shock absorber thoroughly before deciding to replace it. Check all four springs and shock absorbers thoroughly, in the same manner. Do not rush through the job. Being thorough will ensure the safety of the vehicle and of its passengers.

8.Repair or replace any damaged or worn springs and shock absorbers