04/25/2026
We'd like to take a minute to discuss suspension bushings, more specifically, polyurethane vs rubber bushings.
Rubber bushings are usually constructed with an inner and outer steel sleeve. The rubber on these bushings is attached to the steel sleeves and cannot rotate seperately from them. This contruction requires the rubber to flex as the suspension moves up and down. This is the style of bushing that you will find on factory vehicles as they give the best ride quality and do not require any regular mantenance.
Polyurethane bushings do not have as much flex or distortion as rubber bushings. This requires that they be constructed differently. They still use an inner steel sleeve, but only sometimes have an outer sleeve. Sometimes the control arm or other component will act as the outer sleeve. Because these bushings do not flex as much, the bushing and the steel sleeves are not attached to each other, and the bushing needs to be able to rotate inside the sleeves. This is where the main downside of polyurethane bushings lies. These bushings need to be greased somewhat regularly or they will dry up, start making noise, and potentially cause binding in the suspension.
Here's an example where polyurethane bushings should not be used. This car came to us just as shown. The bushings in the upper control arms were either installed without being greased properly, or the grease has all worn off. The bushings are now extremely tight and noisy, and there is no way to regrease them without taking the control arm out of the car, which would require the front end to be realigned. Something like this should have a factory style rubber bushing that won't require any regular maintenance.
If you decide to buy polyurethane bushings for your car, or components that have them already installed, we highly recommend looking for something that has a grease fitting installed. If it isn't greasable, be prepared to take that part off at some point when it needs to be regreased.
