Transportation TrainingTransportation Training

Wheel AlignmentWheel Alignment

Why Align the Wheels? Why Align the Wheels? Correct Wheel alignment is essential to vehicle

safety.Improve Handling AbilityMaximum Fuel Economy

Prolong Tire Life

By Allowing the tires to roll freely without scuffing or slipping sideways under any operating conditions

Alignment Angles and Alignment Angles and AdjustmentsAdjustments 1. Caster

2. Camber3. Toe-in/out

4.Ride height

5.Thrust Angle or Tracking

6.Steering Center

Non adjustable

7.Scrub Radius

8.Steering Axis Inclination

9.Toe-Out on Turns

CasterCaster Caster is the forward or

rearward tilt of the Steering

Knuckle

When viewed from the side of the vehicle.Measured in degrees.

Caster is adjustableTo increase Directional Control of the vehicle

To compensate for Road Crown Pull.

To help the wheels to return to the straight-ahead position.

Positive for power steering

Negative for manual steering

CamberCamber Camber is the inward or

outward tilt of the top of the wheel and tire

assembly

When viewed from the front of the vehicle. Measured in degrees.

Camber is adjustableTo prevent tire wear on the

outer or inner tread

To load the larger inner wheel bearing vs. the smaller outer bearing.(Positive)

To aid steering by placing the weight on the inner end of the spindle and reducing scrub radius.

Common camber settings are ¼ to ½ degree positive

Toe-in /Toe-Toe-in /Toe-outout

Is the inward or outward direction of

both left and right wheel

and tire assemblies

When viewed from above the vehicle. Measured in inches or millimeters or degrees.

Toe-in is when the front tires are closer at the front than at the rear

Common Settings:

Front Wheel Drive 1/16” or 1.5 mm

Rear W Drive 1/16” to ¼” or 1.6 to 6 mm

Ride HeightRide Height Ride height is measured from the rocker panel

to the ground surface

Measured in inches or centimeters at 4 locations close to each wheel

Thrust Angle or Thrust Angle or TrackingTracking

Thrust angle is the direction that the rear wheels are

pointing in relation to the

center line of the vehicle.

Thrust angle should be zero and is only adjustable on certain vehicles.

Steering Wheel CenterSteering Wheel CenterSteering center is simply the fact that the steering wheel is centered “level”

when the vehicle is traveling down a straight

and level road.

Adjusted by toe settings and affected by thrust angle.

Common AdjustmentsCommon AdjustmentsThe most common

adjustments are Caster, Camber, Toe, and

Thrust angle

Pre Alignment Pre Alignment InspectionInspection

Worn TiresTire PressureTire Size and TypeWheel or Tire runout

Cradle AlignmentLoose Wheel BearingsRide Height and WeightWorn Steering and

Suspension Components

Tech Tip: Always Road test the vehicle before doing a wheel alignment. This helps to detect problems, like pulling or worn components.

Reading Tire WearReading Tire Wear

Abnormal Tire Wear is Caused by

Incorrect Tire PressureExcessive CamberIncorrect Toe Settings

Lack of RotationUnbalanced TireUnder Rated TiresDriving Conditions

Making AdjustmentsMaking AdjustmentsCaster is adjusted by moving the control arm so that the ball joint

moves toward the front or rear of the vehicle and is not always

adjustable.

Making AdjustmentsMaking AdjustmentsCamber is changed by moving the

control arm in or out without moving the ball joint forward or

rearward..

Making AdjustmentsMaking AdjustmentsToe angle is adjusted by

lengthening or shortening the tie-rods..

.

Suspension TypesSuspension TypesMac Pherson

Strut Suspension with Rack and

Pinion Steering

Conventional Suspension & Parallelogram Steering

ASE-Type QuestionsASE-Type QuestionsAutomotive

ServiceExcellence

Chapter 74

Transportation TrainingTransportation Training

Wheel AlignmentWheel Alignment

The End