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Replacing Rear Bushings
Replacing Rear Bushings
by Paul Grimshaw
How many times has the interior comfort of a Volvo sedan or wagon been undermined by the cacophony
of sounds and sensations that accompanies a drive over less-than-perfect roads? I don't know the answer,
but I suspect that it occurs somewhere in America every day.
An owner's first response is often to replace the car's shock absorbers. This certainly improves comfort
and control, but the suspension continues to feel its age. After months of aural discontent and imprecise
handling, the car is assessed to be a victim of too many miles and too many bumps. A "for sale" sign
appears in the window.
This article will focus on the role that bushings play in maintaining a good quality ride in 200-, 700-, and
900-series cars.
What Are Bushings?
Bushings are flexible cylindrical cushions fitted between moveable components to attenuate vibration
and assist in alignment. Typically used between suspension components, bushings are constructed of
synthetic rubber, polyurethane, special plastics or aluminum.
Bushings work by transferring the kinetic energy of moving parts into heat. Repeated heat cycles and
oxidation eventually causes the bushings to shrink, harden and lose their elasticity. When this occurs, the
bushings can no longer adequately attenuate vibration or assist in the alignment of components. The
result is increased transmission of noise, vibration and harshness throughout the chassis.
Bushing Materials & Characteristics
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