Why Polyurethane Bush is better than Rubber Bush?
What is Polyurethane?
Polyurethane is a term used to describe a wide ranging family of elastomers (any compound exhibiting the characteristics of natural rubber; stretchy and elastic.). Poly meaning “many” and “urethane” the classification of the chemical structure. Polyurethane or urethane for short, is used as a solid cast material (bushings). Polyurethane can be as soft as a rubber band or as hard as plastic.
Is there a benefit over rubber?
Many advantages can be found over rubber. Depending on the formulation, urethane has a higher load-bearing capacity, greater tear strength, better compression set, greater abrasion resistance, tolerant to greases, oils and ozone and allows for more unique designs.
What’s the difference between rubber and urethane?
Rubber is the sap of trees found mostly in tropical climates. The sap is altered by mixtures of carbon (why it’s black) and mineral oils and various fillers. Polyurethane is completely chemical or man-made. Because rubber is a biodegradable product it is affected by ozone and will over time dry rot and degrade, while urethane will keep going and going.
Does urethane squeak?
In a word, no. Squeaking is caused by high frequency vibrations that can be heard rather than felt. It is usually caused by lack of lubrication, poor installation, incorrect part, urethane that may be too hard for the application. In sway bar mount applications, most squeaking comes from not cleaning the sway bar prior to installing the bushings and not using our “squeak proof” grease! Additionally, all our dynamic application bushings feature grooves or splines to hold in our waterproof, highly adhesive, high temperature and pressure grease.
Does urethane ride really hard (harsh)?
The original rubber bushing or mount was fairly soft which helped to attenuate noise and vibration that is generated by the tires and road surface. Increasing the hardness of the bushing either with harder rubber, urethane or even bronze, will allow more transmission of noise and vibration. Some manufacturers formulate the hardness and design to reduce this effect. A softer urethane bushing allows the vehicle to perform better without the harshness, even over the same hardness rubber piece.
Are all urethane bushings the same? Same material, same hardness?
No, no and no. Each manufacturer has their own idea as to the best way a bushing should be designed. We select materials based on physical performance and choose the right hardness for each application.
Can urethane be used for all types of vehicles?
Urethane can be formulated for anything from an MG to a Cadillac to a rough and ready 4X4 or lowered Honda street car.
What is the Steering Rack Mounting Bushings all about?
The power steering rack is the part that converts the steering wheel input into a usable side-to-side direction. The steering gear, or steering rack, is mounted to the frame of the vehicle. Since mounting it directly to the frame would cause extreme road noise and a ‘noisy’ steering feel, it is mounted by means of steering rack mounting bushings. These steel sleeves surround every mounting point on your vehicle’s steering rack. The sleeves themselves are also wrapped in a neoprene rubber. Together, bushings are able to dampen the natural vibration that occurs when driving and allow you to operate your vehicle without having excessive road noise or feedback in the steering wheel. If the steering rack mounting bushings are worn or have come loose, you will have a clunk in your steering wheel and less responsive steering overall.
Keep in mind:
· Have a wheel alignment performed after the steering rack (or "steering gear") mounting bushings are replaced.
How it's done:
· The vehicle front wheels are put straight and the vehicle is lifted and supported on jack stands
· The defective steering rack mounting bushings are removed
· The new steering rack mounting bushings are installed
· The front tires are installed and the vehicle is removed from jack stands
· The vehicle is started and checked for steering rack operation
The steering gear or rack is checked with every suspension and steering inspection performed on your vehicle. The steering rack mounting bushings are included during those inspections. If the steering rack mounting bushings are identified as worn or loose, have one of our expert mechanics replace them.
What common symptoms indicate you may need to replace the Steering Rack Mounting Bushings?
· Steering jerks are inconsistent
· When you take bumps, you feel a “clunk” in the steering column
How important is this service?
Steering rack mounting bushings are essential for the operation of your vehicle. While you can definitely drive with bad bushings, poor steering control could end in an accident.