Operation CHARM: Car repair manuals for everyone.

Wheel Alignment

BODY REPAIR FUNDAMENTALS

WHEEL ALIGNMENT

Wheel alignment refers to the positioning of each of the four wheels with respect to the body. Correct wheel alignment provides:
- Light steering wheel handling
- Positive steering wheel operation
- Proper stability of steering wheel
- Reduced tire wear
When repairing a damaged vehicle, particularly one with a strut suspension, an error in body alignment will directly affect wheel alignment. Therefore, correct adjustment of body alignment is very important.




1. CAMBER ANGLE

Tilting of the wheels from the vertical is called the camber angle.




2. CASTER ANGLE

Rearward tilting of the strut when viewing the front wheel from the side.
(As shown in the figure to the right, when caster is tilted rearward, the front wheels are pulled backward by the tires contact to the road. This reduces sideways vibration in the front wheels and also makes it easier for the wheels to recover their forward position after being turned. This "caster effect", helps keep the vehicle stable in the straight ahead position and improves steering correction.)




3. KINGPIN ANGLE
Inward tilting of the strut when viewing the front suspension from the front.




4. TOE-IN

Toe-in refers to the turning in of the front wheels.

TOE-IN = B - A

Its purpose is to prevent slipping and scuffing of the tires on the road.

5. NON-STANDARD CONDITIONS CAUSED BY IMPROPER WHEEL ALIGNMENT

1. IMPROPERLY ADJUSTED CAMBER
- Heavy steering wheel operation
- Slow steering wheel return
- Uneven tire wear

2. IMPROPERLY ADJUSTED CASTER
- Excessive caster... Heavy steering wheel operation
- Insufficient caster .. Slow steering wheel return
- Imbalance between left and right... Car may be pulled to the side with the smaller caster angle.

3. IMPROPERLY ADJUSTED KINGPIN INCLINATION
- Heavy steering wheel operation
- Heavy shock loads transmitted to steering wheel
- Slow steering wheel return

4. IMPROPERLY ADJUSTED TOE-IN
- Heavy steering wheel operation
- Car may be pulled to one side.
- Uneven tire wear