Figure 8-15.Torsion bar.
SUSPENSION SYSTEM SERVICE
A suspension system takes a tremendous
"pounding" during normal vehicle operation. Bumps
and potholes in the road surface cause constant
movement, fatigue. and wear of the shock absorbers, or
struts. ball joints, bushings, springs, and other
components. Suspension system problems usually
show up as abnormal noises (pops, squeaks, and
clunks), tire wear, steering wheel pull, or front end
shimmy (side-to-side vibration). Suspension system
wear can upset the operation of the steering system and
change wheel alignment angles. Proper service and
maintenance of these components greatly increase
roadability, reliability, and vehicle life.
Suspension Bushing Service
Rubber bushings are commonly used in the inner
ends of front control arms and rear control arms. These
bushings are prone to wear and should be inspected
Worn control arm bushings can let the control
arms move sideways. This action causes tire wear and
steering problems. To check for control arm bushing
wear, try to move the control arm against normal
movement. For example, pry the control arm back and
forth while watching the bushings. If the control arm
moves in relation to its shaft, the bushings are worn and
must be replaced.
Generally, to replace the bushings in a front
suspension requires the removal of the control arm.
This usually requires the separation of the ball joints
and compression of the coil spring. The stabilizer bar
and strut rod are also unbolted from the control arm.
The bolts passing through the bushings are then
removed which allows for the control arm to be
removed from the vehicle. With the control arm placed
in a vise, either press or screw out the old bushings and
install new ones.
With new bushings installed, replace the control
arm in reverse order. Torque all bolts to the
manufacturers specifications. Install the ball joints
cotter pin. Check the manufacturers service manual
for information concerning preloading control arm
Always refer to the manufacturers service
manual for exact directions and specifications.
This will assure a safe, quality ride.
Ball Joint Service
Worn ball joints cause the steering knuckle and
wheel assembly to be loose on the control arm. A worn
ball joint may make a clunking or popping sound when
turning or driving over a bump. Ball joint wear is
usually the result of improper lubrication or prolonged
use. The load-carrying ball joints support the weight of
the vehicle while swiveling into various angles. If the
joints are improperly lubricated (dry), the swiveling
action will cause them to wear out quickly.
Grease fittings are provided for ball joint
lubrication. If the ball joint has a lube plug, it must be
removed and replaced with a grease fitting. Using a
hand-powered grease gun, inject only enough grease to
fill the boot of the ball joint. Do not overfill the boot,
because too much grease will rupture the boot. A
ruptured boot will allow dirt to enter the joint, which
causes them to wear out quicker.