Cars Simplified: Everything Automotive Explained


Bushings are components which take up the space between two parts which move, but not much, such as points in the suspension system. They are commonly made out of rubber, silicone, or other similar flexible materials. Bushings often wear out instead of metal when their materials decay, or the grease is depleted, and can be replaced relatively cheaply.


Rubber is the most common material used for chassis bushings. It is relatively inexpensive and easy to mold into shape. There is a lot of flex offered by rubber, which makes for a smooth ride but sometimes results in delayed steering response.


Sometimes metal is used as the main bushing material, but it is more common for metal to reinforce rubber or other materials. Many soft material bushings have a metal shell to push in.


Polyurethane bushings are a common handling upgrade, but are sometimes also used as original parts when additional durability is required. Polyurethane is available in various levels of stiffness, but many manufacturers decide on a durometer (stiffness) for a given application and the buyer isn't offered a choice or even knowledge of the durometer upon purchase in many instances.

In some applications where bushings are a simple design, performance car builders can contact a manufacturer of bushings and have them manufactured on demand or ordered from inventory based on dimensions given and durometer requested. These options allow a chassis builder precise control over play allowances between parts.

While not always the case, most polyurethane bushings are easier to install than press-fit rubber bushings, and last longer as well.

Bushingless Designs

For a truly precise racing suspension, bushingless connections are used. This practically eliminates all play between suspension and steering components. Every road iregularity that disagrees with the angle of the tire can be felt in the steering. All the noise generated by the road and tire interaction is heard from the inside of the vehicle. It is a serious change to the vehicle that requires frequent maintenance and would be an awful experience on many public roads.

Sway Bar Bushings

Replacing Original Bushings With Polyurethane

This video shows the process in removing original bushings from a Pontiac GTO so that they can be replaced with polyurethane. This upgrade aims to improve the handling characteristics of the car. Video by Cars Simplified, music by Sawtooth.

Replacing rubber bushings with polyurethane will make suspension movement more precise, which usually translates to better handling, but the trade-off is that road irregularities will be more noticeable, especially with a full switch over and with stiffer springs. Vehicles meant to be comfortable daily drivers may actually be made worse by this upgrade, unless the suspension is fairly soft to begin with.