Alignment: Description and Operation

Camber
Camber (C) refers to the wheel leaning in or outwards. The angle is considered positive if the wheel leans outwards and negative if the wheel leans inwards.
Camber can be adjusted within certain limits.





Road holding is better with negative camber because the wheel stands upright when the body rolls.





Positive camber gives better feel for the road through the steering wheel. With an extreme wrong camber the tires wear unevenly.





Caster
The caster angle (B) is the angle between vertical line (A) and a line which goes through the center of the lower ball joint and upper bearing (in other words a line through the spring strut) Caster encourages the wheel to travel straight forward and so makes steering easier. In addition the greater the caster angle the greater the self-centering effect.

Note! Caster angle cannot be adjusted.





King pin inclination
Originally king pin inclination (D) referred to king pin lean. Because the car does not have a king pin the inclination corresponds to the angle between the vertical line (A) and a line through the spring strut.
A real king pin inclination ensures that the wheel turns easily and retains a self centering effect.
King pin inclination cannot be adjusted.

TOE-IN:

Toe-in





With toe-in the front part of the wheel points inwards. Toe-in can either be measured as an angle or as a difference between measurement a and b. See illustration.
Correct toe-in gives the correct feeling from the road through the steering wheel and assists directional stability.
The toe-in angles are adjusted by the tie-rod length.

Note! Toe-in should always be adjusted in relation to the car's driving geometric axis (thrust line) which is derived from the rear wheel toe-in. See Checking and adjusting the wheel alignment.






Toe-out

Toe-out or incorrect toe-in cause vibrations that increase tire wear. Tires slide sideways. Too much toe-in causes wear to the outer shoulders of the tires.

Ackerman angles
The wheels follow different radii when cornering.
In order to ensure that they turn at the same center, and to minimize tire wear the front wheels must be offset from each other. This relationship is determined by the design of the tie rod and steering arms and cannot be adjusted.