90 Auto Suspension and Steering
bushings. Most upper control arms have two bushings. The
lower control arm may be installed on the frame with one
or two bushings, depending on control arm design.
Alignment adjustment devices may be installed at the
control arm mounting points.
A strut rod is attached to all single-bushing lower con-
trol arms and some two-bushing lower control arms. A
stabilizer bar of some type is always installed on indepen-
dent front suspensions.
Nut
Washer
Upper
mounting
Upper
seat
Spring
seat
Bumper
Dust
boot
Strut
cartridge
Coil
spring
Figure 5-8. A typical piston bumper is used to absorb shock as the strut bottoms out. (Mazda)
Upper stop
Sleeve
Upper mount assembly
Bearing
Spring seat
Jounce bumper
Dust cover
Strut rod
(shock absorber)
Strut tube
(shock absorber)
Figure 5-9. The upper stop prevents the piston rod from being
pulled out of the upper strut mount.
Piston
rod nut
Fender
Piston rod
Upper
mounting
nuts
Dust cover
Lower mounting
nuts and bolts
Strut
Figure 5-10. This strut uses a dust shield to protect the piston
rod from dirt, water, etc. (Moog)
Short-Long Arm Suspension Design
All conventional suspensions use the short-long arm
(SLA) design. In this design, the upper control arm is
shorter than the lower control arm. When the wheel moves
over a bump, the upper arm travels in a tighter arc than the