Bushings are small rubber pieces that serve to connect all of the metal parts and pivot points in a suspension system. Their main functions are to absorb vibrations from the engine and provide a smoother ride for the driver and passengers, allow the metal parts of the suspension system to move around, and prevent unnecessary wear and tear on the rest of the suspension system.
Rubber can degrade and become damaged more easily than metal, so it is important to keep an eye on the bushings. If the rubber hardens or tears and goes unnoticed, it can cause damage to the components of the suspension system, which will be more expensive and time-consuming than replacing the bushings. Diagnosing bushing failure can be difficult and the symptoms are easy to associate with other problems.
If you suspect your bushings may be nearing the end of their life, you can perform a couple of diagnostic tests to determine if they are the source of the problem. Taking the car for a drive on bumpy roads can be a good way to find this out. When the brakes are not engaged, listen closely for squeaking, clunking and high-pitched noises during the drive, especially when riding over bumps. This could mean that one of more bushings has cracked or worn out.
Another sign of problematic bushings is a heavy clunking sound when you attempt to turn the steering wheel. If the bushings are bad, the car might pull to either side while driving down a straight road, but this could also indicate an alignment problem - which may or may not be related to the bushings. You can check by inspecting the tire tread. Excess wear on the inner or outer side of the tires typically means that there is a suspension misalignment. A scalloped pattern could point to an issue with the struts or shocks, which may also be tied into bushing problems.
Next, pop the hood. Locate one of the strut towers in the fender well. Right below the spacer at the top of the mount will be a bushing. Inspect it for visible damage and apply some pressure to the front fender to test the suspension system. Watch the bushing while you are doing this and look to see if it moves at all during the process. Any movement indicates that it is time to replace the bushing, and you can do this for each wheel.
When you need to replace a bushing, you should consider doing the same for others, at least the ones that serve the same function in different areas of the vehicle. This way they will continue to deteriorate at the same rate and you will need to replace them less frequently.