Problems with your car's suspension usually exhibit symptoms like abnormal pops, clunks or squeaks; unusual tire wear patterns; steering wheel pull; and front end shimmy (a side-to-side vibration of the front wheels). Each of the following six sections explains where such problems occur and how the problems can be diagnosed.
If your car rides poorly on rough roads, chances are the problem is attributable to worn shock absorbers. When diagnosing for this problem, push down a corner of the car and count how many bounces result when it is released. Good shocks will only bounce two or three times. Worn shock absorbers should be replaced.
If your vehicle's height looks low and it appears to be settling toward the axles, have the suspension springs checked out. Old, tired springs can alter the curb height of your car as well as cause misalignment of the wheels, and can affect the ride as well. A mechanic can safely replace worn springs.
Does your car make unusual clunking or popping noises when turning or when going over a bump? This might indicate a worn ball joint, which can happen if it is not lubricated properly or has been in use for a prolonged period. Two ways to tell if a ball joint is worn include checking the wear indicator or measuring the amount of play in the joint. Worn ball joints should be replaced.
A car's suspension system employs rubber bushings at the inner ends of the control arms (which keep the steering knuckle, bearing support or axle housing in position while the wheel moves up and down). The bushings cushion the control arms as they operate, and when the bushings are worn, steering problems and abnormal tire wear can occur. One test for worn bushings is to try to push the control arm in such a way that goes against its normal motion. If the control arm moves with respect to its shaft, the bushings are worn and should be replaced.
The most common failure of a car suspension that utilizes MacPherson struts is related to their integral shock absorbers. In the same way as with ordinary shock absorbers, these shocks can leak, which reduces the dampening action for which they were designed. As a result, your car might have a poor ride.
If your car's suspension is controlled by a computer for ride height, stiffness or for adjustable handling characteristics, you can use a scan tool to troubleshoot any problems. Faulty sensors, solenoids, actuator motors, relays or failure of the compressor motor can be detected with a scan tool, and you can use the information to diagnose the problem.
