6Camber PullWhen the camber is more than ½ degree different from one side to the other, the car will pull or drift.
7CASTER Forward or rearward tilt of the steering knuckle at the top Measured in degrees of a circleProvides straight line driving and steering wheel return#1 Pull rule.Does NOT effect tire wear
8Measuring CasterCaster is measured in degrees of a circle from true vertical.If the steering knuckle leans toward the rear of the car at the top that is positive caster.If the steering knuckle leans toward the front of the car at the top that is negative caster.
9How Caster Works There are two points of importance: The point of contact.The point of lead.The vehicle will always follow the point of lead.
10Effects of CasterIf the difference in the caster angle is more than ½ degree from side to side, the car will pull to the side of the most negative caster.Caster has no effect on tire wear.
11TOE-IN TOE-OUTToe is the difference in distance between the front and rear of the front wheels.Measured in inches, millimeters or degrees.#1 Tire wearing angle.Does not effect handling.
12Measuring ToeToe is typically measured in inches. (fractions of inches)If it is off, the tires will wear feather edged. Also the steering wheel spoke is usually crooked.
13STEERING AXIS INCLINATION Gives directional stability much like casterNon-adjustableOnly changes when parts are bentVery important to check in collision work
14TURNING RADIUS or TOE-OUT ON TURNS Changes radius for inboard and outboard wheel while turningNon-adjustableImportant to check if doing collision work
15Vehicle Thrust LineThe rear wheels determine the path of the vehicle. Not the front wheels as commonly thought.
16Setting Up the CarCar suspension & steering must be checked out prior to alignment and repaired.Pull car on the rack correctly.Set rack on alignment stands.Connect alignment wheel reflectors.Punch in alignment specifications.
17Rolling CompensationThis runs out the wheel clamp and measures camber, toe, thrust line and set back.
18Checking Caster and S.A.I. The wheel must be turned to reveal caster and SAI.
19Interpreting the results. On the rear, adjust camber the then toe.On the front adjust camber, caster and then toe.