This document discusses various types of vehicle suspension systems and their components. It describes solid axle, twin I-beam, short arm-long arm, and McPherson strut suspensions. Suspension components like springs, shocks, steering gears, and alignment angles are also outlined. Leaf springs, torsion bars, coil springs, and progressive coil springs are explained as well as how to adjust their strength. Finally, concepts such as camber, caster, toe, ride height, 4-wheel alignment, and tire rotation are summarized.
2. Suspension Types
Solid Axle
Good load capacity
Poor dynamic
characteristics
Twin I Beam
Good load capacity and
travel
Poor tire wear & handling
Short Arm-Long Arm (SLA)
Independent suspension
Good tire wear & load
carrying capability
McPherson Strut
Good handling
characteristics
Light weight
3. Suspension Components
Suspension components must perform the
following
Turn wheels left and right
Maintain alignment angles through wheel travel
Provide for nice ride on various road surfaces
Support the weight of the vehicle
4. Springs
Leaf Spring
Torsion bar
Coil Spring
Progressive Coil
Spring
A Spring is designed
to maintain the
vehicle ride height,
support the vehicle’s
sprung weight and
supply the desired
amount of ride
comfort.
5. Take a piece of flat metal stock,
harden it a bit to make it tough
and you have a …
10. Torsion Bar
To make a torsion bar weaker,
use a smaller diameter bar or
longer bar.
To make a torsion bar stronger,
use a larger diameter bar or
shorter bar.
11. Take our torsion bar, wind it into
a round shape and you have
a…
13. Coil Springs (same rules as torsion
bar)
To make a coil spring weaker, use
a smaller diameter coil wire or
longer coil wire.
To make a coil spring stronger,
use a larger diameter coil wire or
shorter coil wire.
14. Shock / Strut
A Shock or Strut is
responsible for
dampening spring
oscillation.
Active Suspension
16. Suspension Components
Low weight
Good feed back to
driver
Minimal wear parts
Can be manual or
hydraulic
Heavy duty design
Can be manual or
hydraulic
Rack and Pinion Steering
Gear
Conventional Steering Gear
Box
19. Steering Components SLA
Sway Bar
Pitman Arm
Center Link
Inner Tie Rod
Outer Tie Rod
Steering Knuckle
Upper Ball Joint
Lower Ball Joint
Upper Control Arm
Lower Control Arm
Tie Rod Sleeve
20. Steering Components Rack &
Pinion
Outer Tie Rod
Inner Tie Rod
Steering gearBellows Boot
Mounting bolts
Bellows Boot
Jam nut
21. Alignment Angles
4 Wheel alignment is
responsible for the
following
Directional Stability
Reduced Tire Wear
Cornering
Returnability
Predictability
Tracking
Road Isolation /
Feedback
Centered Steering
wheel
22. Camber
Camber is
measured in
Degrees from true
vertical
Positive Camber
Wheel tilts outward
Negative Camber
Wheel tilts inward
25. Caster
Caster measured in
degrees from true
vertical using the
steering axis
Positive Caster
Steering Axis tilts
back
Negative Caster
Steering Axis tilts
forward (non used)
26. Caster
Is non wearing angle
Causes pull if exceeds ½ deg difference side
to side
Typical Caster readings are 2-6 degrees
positive
27. Toe
The difference in the
distance measured
between lines drawn
through the center of
tires on the same axle.
Measurements are
taken at the front and
rear of the tires.
Typical Toe reading
1/16 “+- 1/32
Toe is the fastest tire
wearing angle
30. 4 Wheel Alignment
All suspension
components
must be tight
The vehicle
should be
normally loaded
Tire pressure &
size correct
All 4 wheels
should be
aligned