Alignment: Description and Operation

Wheel Alignment Angles
Camber, caster and toe are adjustable on the front suspension system. Only the toe is adjustable on the rear suspension system. Camber and caster are adjusted by means of eccentric cams on the lower arm mounting bolts. The front toe is adjusted by use of the front tie-rod. The rear toe is adjusted by the use of toe link assemblies connecting the knuckles to the rear sub-frame.

Camber

Negative Camber





Positive Camber





Camber is the vertical tilt of the wheel when viewed from the front. Camber can be positive or negative and has a direct effect on tire wear.

Caster









Caster is the deviation from vertical of an imaginary line drawn through the ball joints when viewed from the side. The caster specifications will give the vehicle the best directional stability characteristics when loaded and driven. The caster setting is not related to tire wear.

Toe

Positive Toe (Toe-In)





Negative Toe (Toe-Out)





The vehicle toe setting:
- affects tire wear and directional stability.

Ride Height

NOTE:
All ride height measurements are carried out with vehicle empty and 9 liters of fuel in the tank (showroom condition). The vehicle must be driven above 40 km/h (25 miles/hour) for a minimum of five minutes to make sure that the reservoir is full.

Front Ride Height Measurement









Rear Ride Height Measurement









Wheel Track









Crabbing









Crabbing is the condition in which the independent rear suspension (IRS) system is not square to the chassis. Heavily crowned roads can give the illusion of crabbing.

Wander
Wander is the tendency of the vehicle to require frequent, random left and right steering wheel corrections to maintain a straight path down a level road.

Shimmy
Shimmy, as observed by the driver, is rotational oscillations of the steering wheel which may come and go over time, generally resulting from wheel and tire imbalances.
Shimmy can be experienced at any speed but generally between 80 to 145 km/h (50 to 90 miles/hour) and is most often experienced on smooth roads at steady speeds.

Nibble
Sometimes confused with shimmy, nibble is a condition resulting from tire interaction with various road surfaces or brake disc irregularity and observed by the driver as small rotational oscillations of the steering wheel.

Poor Returnability of the Steering
Poor returnability of the steering is used to describe the poor return of the steering wheel to center after a turn or the steering correction is completed.

Drift/Pull
Pull is a tugging sensation, felt by the hands on the steering wheel, that must be overcome to keep the vehicle going straight.
Drift describes what a vehicle with this condition does with hands off the steering wheel.
- A vehicle-related drift/pull, on a flat road, will cause a consistent deviation from the straight-ahead path and require constant steering input in the opposite direction to counteract the effect.
- Drift/pull may be induced by conditions external to the vehicle (i.e., wind, road crown).

Vague On-Center Feel
Vague on-center feel is characterized by little or no buildup of turning effort felt in the steering wheel as the wheel is rocked slowly left and right within very small turns around center or straight-ahead (under 20 degrees of steering wheel turn). Efforts may be said to be "flat on center".
- In the diagnosis of a roadability problem, it is important to understand the difference between wander and vague on-center feel.