Car maintenance can be daunting. There are a number of small parts which serve an important purpose and have to be checked, repaired and replaced regularly in order for the car to last. Car owners need to have a good working knowledge of what these parts are and how they work, so that when something goes wrong with their vehicle they can diagnose the problem and know the appropriate solution.
Bushings are one of those small but important parts. They are mounting connections used to connect all the articulating metal parts and pivots in the suspension system of the car together. There are a number of uses for bushings in a variety of machinery, but in a car bushings serve three basic purposes.
First of all, bushings make the car ride smoother. When a car is in motion, friction and bumps on the ground cause a great deal of shock and tremors to travel up the car tire and into the chassis or base of the car. This can cause the interior of the car to shake and rattle a good deal, and that kind of jostling makes for very uncomfortable car trips. Bushings cushion the joints and absorb the shocks and vibrations before it can be transferred into the chassis, making car journeys a lot easier on the passengers.
Secondly, bushings allow a small amount of motion. To fulfill the first purpose, absorb shocks, a bushing has to be very rigid. However, it cannot be totally rigid, because that would cause the whole car to stop functioning. The car has a number of movable parts, like the control arm joint, which are connected to the bushings. If the bushings were fully rigid, the control arm joint would not be able to move. Similarly, other car parts attached to bushings could not be articulated if the bushings never moved. Therefore, it is important that the bushings be able to absorb shock while still allowing the motions necessary for the functioning of the car.
Finally, they help save money on expensive parts. Cars are very heavily used. There is always a great deal of wear and tear on them, both outside on its paint and frame, and inside on all the parts which actually make the car move. Some of these parts are very expensive, or they are extremely hard to replace, or both. Bushings protect these parts by absorbing a lot of the wear and tear. When they are worn out, bushings can be very easily replaced, and the cost of the new bushings and the replacement charge is much lower than if it were a more expensive part.
Bushings are usually made of rubber or polyurethane. There are many different materials for bushings, depending on the environment where they will be used. Bushings with a high durometer index are more rigid and better at shock absorption than those with a lower durometer index. Bushings located near car engine filters are exposed to a great deal of heat, so they need to be made from material like Santoprene which are heat resistant. If the bushings need to be rotated then it needs chrome surfaces, and some older bushings are made of material which become noisy at certain temperatures. Modern bushings are made of sunthetic material impregnated with graphite and have grease grooves so that they last longer and work better.
Bushing problems are very easy to misdiagnose and can make people replace parts which needed no replacement. When installing bushings the installer has to be careful that he did it properly, because wrongly installed bushings can lead to lower car performance.