Are struts simply oversized shock absorbers?
A strut performs the same ride control functions
as a shock absorber, but it is also an integral part of the suspension
rather than an add-on component.
On most strut suspensions (except some late
model Honda applications that have "wishbone" suspensions),
the struts replace the upper control arms and ball joints.
The 1986 Honda Accord has a rear double-wishbone
suspension. The strut plays no role in wheel alignment in this arrangement,
serving only to carry the vehicle's weight and to dampen shocks.
Struts serve as the steering pivots and on
most applications (except certain Ford suspensions like the Mustang
and T-Bird), they also carry the springs. On some rear-wheel drive strut
suspensions, the wheel spindles are part of the front struts (which
adds to their cost). The same is true on some front-wheel drive rear
Another important difference between struts
and shocks is that struts also affect wheel alignment, whereas shocks
do not. A bent strut or a mislocated strut tower can cause tire wear
and steering pull problems.
Many struts are also rebuildable. On many
import cars, the struts have an internal cartridge or wet elements that
can be replaced by unbolting the upper strut mount, swinging the strut
out from under the fender, disassembling the upper strut components,
and replacing the internal components with a new cartridge.
On most domestic applications, however, the
entire strut must be replaced. Replacement options include both nonpressurized
and gas pressurized versions, the latter offering all the same benefits
as gas shocks.
One often overlooked strut component that
usually needs attention is the upper bearing plate that sits atop the
strut. This plate supports the weight of the vehicle and serves as the
upper pivot point for steering. If corroded or worn, it can make noise,
increase steering stiffness and reduce steering returnability.