Chapter 79 POWERPOINT

Use the textbook to define these Technical Terms:

1. alignment

2. alignment machine

3. camber

4. caster

5. dog tracking

6. eccentric bolt

7. feathered edge

8. road crown

9. steering axis inclination

10. toe

Use the textbook to answer these discussion questions:

1. What is the main purpose of a wheel alignment?

Read the chapter summary below:

Summary

■ The main purpose of wheel alignment is to make the tires roll without scuffing, slipping, or dragging under all operating conditions.

■ Caster is basically the forward or rearward tilt of the steering knuckle (spindle support) when viewed from the side of the vehicle.

■ Road crown is the normal slope toward the outer edge of the road surface.

■ Camber is the inward or outward tilt of the wheel and tire assembly when viewed from the front of the vehicle.

■ Toe is determined by the difference in distance between the front and rear of the left- and right- hand wheels.

■ Front-wheel-drive and rear-wheel-drive vehicles normally require much different toe settings.

■ Steering axis inclination is the angle, away from the vertical, formed by the inward tilt of the ball joints, king pin, or MacPherson strut tube.

■ Toe-out on turns, also termed turning radius, is the amount the front wheels toe-out when turning corners.

■ Tracking, also called thrust line, refers to the position or direction of the two front wheels in relation to the two rear wheels.

■ Reading tires is done by inspecting tire tread wear and diagnosing the cause for any abnormal wear.

■ Camber is usually adjusted right after setting caster.

■ Toe is adjusted by lengthening or shortening the tie-rods.

■ Turning radius gauges measure how many degrees the front wheels are turned right or left.

■ A caster-camber gauge is used with the turning radius gauge to measure caster and camber in degrees.

■ The alignment rack consists of ramps, turning radius gauges, and one of several kinds of equipment for measuring alignment angles.

■ A modern alignment console typically consists of a color monitor, keypad, and computer, all mounted in a roll-around cabinet.

■ Alignment heads mount on the vehicle wheels to check caster, camber, and toe.

■ After completing your wheel alignment, you should road test the vehicle to check your work.