Alignment: Description and Operation

Suspension System

The front camber and caster are adjusted by loosening the upper control arm bolts which will allow the upper arm to be moved in the slotted frame holes. The LF caster can be adjusted by loosening the lower control arm rearward nut to allow the lower arm to be moved in the slotted frame hole. Front toe is adjusted by the use of the front wheel spindle tie rods. The rear camber is adjusted by replacing the upper arm inboard flagnut with a non-flagnut to allow the arm to be adjusted in the slotted frame holes. The rear toe is adjusted through the use of the rear toe link cam bolt.


Camber

Negative and 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.
- must be checked after adding aftermarket equipment, such as a snowplow.

Incorrect Thrust Angle (Dogtracking)










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 large, consistent, rotational oscillations of the steering wheel resulting from large, side-to-side (lateral) tire/wheel movements.

Shimmy is usually experienced near 64 km/h (40 mph), and can begin or be amplified when the tire contacts pot holes or irregularities in the road surface.


Nibble

Sometimes confused with shimmy, nibble is a condition resulting from tire interaction with various road surfaces and observed by the driver as small rotational oscillations of the steering wheel. For wheel and tire diagnosis, refer to Wheels and Tires.


Poor Returnability/Sticky Steering

Poor returnability and sticky 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, such as wind or road camber.