Introduction to Wheel Alignment

Wheel Alignment

What is Wheel Alignment?

•  Wheel alignment consists of adjusting the angles of the wheels so that they are perpendicular to the ground and parallel to each other. The purpose of these adjustments is maximum tire life and a vehicle that tracks straight and true when driving along a straight and level road. 
• Wheel Alignment is the Measurement of complex suspension angles and the adjustment of a variety of suspension components. It is a suspension-tuning tool which greatly influences the vehicle's handling and tire wear.
• A properly aligned vehicle is one in which all wheels are aimed in the same direction. Some very low tolerance or acceptable error is designed into each vehicle by the manufacturer.
• A vehicle may require an alignment if:

–Damage to any steering or suspension parts or mounting locations

–Engine cradle damage or position change or suspension or steering parts removed

–Damage to major structural components

Basic Alignment Angles:

1. Camber:

Camber

• Camber is the angle of the wheel, measured in degrees, if the top of the wheel is tilted out then the camber is positive, if it's tilted in, then the camber is negative.
• Camber is affected by worn or loose ball joints, control arm bushings, and wheel bearings.
• When the camber is out of adjustment it can cause a pulling problem to the side with the more positive camber. This usually happens when the vehicle has been involved in an accident.
• Camber also goes out of adjustment when the springs sag and causes ride height to change, or when ball joints and or other attached parts are worn or defective.

   

 2.  Caster:

      Caster is the angle of the steering pivot, measured in degrees.

Caster

• If the top of the pivot is leaning toward the rear of the car, then the caster is positive, if it is leaning toward the front, it is negative.
• If the caster is out of adjustment, it can cause problems in straight-line tracking. If the caster is different from side to side, the vehicle will pull to the side with the less positive caster.
• If the caster is equal but too negative, the steering will be light and the vehicle will wander and be difficult to keep in a straight line. If the caster is equal but too positive, the steering will be heavy and the steering wheel may kick when you hit a bump.

    

3. Toe-in: 

Toe-in

• The toe measurement is the difference in the distance between the front of the tires and the back of the tires.
• Front-wheel drive vehicle "pulls" the vehicle, resulting in forward movement of the suspension arms against their bushings. Most front-wheel drive vehicles use negative toe to compensate for suspension movement.
• Toe-in means that the fronts of the tires are closer to each other than the rears. Toe-out is just the opposite.
• An incorrect toe-in will cause rapid tire wear to both tires equally. This type of tire wear is called a saw-tooth wear pattern.
• Unlike caster and camber, which are measured in degrees, toe is most frequently measured in fractional inches, millimeters or decimal degrees.

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