For as long as mankind has been driving, we have been trying to make our commutes smoother and easier on our bums. The horse and buggy days had leather and rubber straps to connect buggy axels to frames. These straps were used to absorb all those bumps when riding on dirt and cobblestone roads. Since then, we have changed our suspension from using metal leafs, to springs, and now a combination of metal and rubber.
Using metal to absorb bumps in the road help reduce the impact from large bumps, but not small ones. Every small bump and vibration in the road could be felt until we started adding rubber seals on each of the joints. You may think that rubber tires would solve this issue, but the rubber on the tire is made to be stiff so that it can handle a lot of pressure from the weight of the car and the air inside. If you want to absorb small bumps you need a light, soft cushion. This is where control arm bushings come into play.
Control arms connect the wheel hub to the chassis and pivot at both ends to allow the wheel hub to move up and down and side to side. Looking at the picture on the left of a front control arm, needs to pivot and rotate with the wheel.
The small rubber seal up top of the control arm in the picture is called a “ball joint“. It looks like a rubber balloon that is squished between a bolt and a bracket on the control arm. The ball joint allows the wheel to pivot from side to side when you turn the car.
The joint on the bottom of the image that is connected to the suspension spring is the “bushing“. This bushing contains a rubber seal inside to help absorb bumps. The bushing also rotates up and down allowing the wheel to move when hitting a bump.
These rubber seals are what eliminate metal from touching other metal so that the driver doesn’t feel every bump in the road. The rubber also helps the car to pivot and turn easier by creating less friction on the joints.
Over time, these bushings dry out, tear, and crack from being constantly used for turning and absorbing bumps while you drive.
How can a driver tell if their control arm bushings are wearing down or need to be replaced? You can see in the picture above the crack around the bushing. Even the ball joint below started splitting apart.
Once the bushings and joints on the control arm reach this state, it can cause a few noticeable signs that tell you it’s time to replace them.
Since these rubber seals eliminate the feeling of small bumps, once they are removed you will begin to feel everything. It will feel like you are riding in a car that has very little suspension. Those small bumps that you didn’t notice before will start to be noticeable.
As the rubber wears off, metal will start hitting metal with each bump. This causes bumps to not only feel worse, but sound worse. You will start to hear and feel little vibrations on the road while you drive and large bumps will make large clunking noises in your car.
As the rubber begins to wear off the joints will start to loosen. The tires will start to wobble when you drive down the road. This will have a similar feeling when your car has an alignment problem. If you place your hands on one of the wheels and push it you will feel more of a wobble. There should be no play in the wheel beyond the acceptable level, so if you feel too much movement, have the car checked.
If the bad control arms are not properly repaired over time, it can cause other issues such as alignment problems, faster tire wear, and cause other suspension parts to crack or break. We recommend that driver’s shouldn’t ignore problems on their cars as it can cause problems to become more expensive.
If you are experiencing any loud noises or other problems with your suspension, feel free to give us a call.
Spotlightautoservice.com specializes in European auto repairs and maintenance. We strive to keep our service cost 40% less than dealerships. Schedule an appointment for your Audi, BMW, Land Rover, Mercedes, Mini Cooper, or Volkswagen with us