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.

1. STEERING AND
SUSPENSION

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 …

6. Rear Leaf Spring

7. Leaf Spring
To make a leaf spring weaker,
use less leafs or longer leafs.
To make a leaf spring stronger,
use more leafs or shorter leafs.

8. Take a piece of round metal
stock, harden it a bit to make it
tough and you have a …

9. Torsion Bar

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…

12. Coil Spring & Progressive Coil
Spring

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

15. Shock Strut

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

17. Rack & Pinion Steering Gear

18. Conventional 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

23. Camber Wear
 Camber causes
shoulder wear on
tires
 Positive Camber
 Outer edge
 Negative Camber
 Inner edge
 Typical Camber
reading +- ¾
Degree

24. Camber Wear

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

28. Toe
Toe In Toe Out

29. Ride Height should be verified before
alignment

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

31. Tire Rotation

32. End Steering and
Suspension