Chapterhahapterpter Wheel Alignment Name80 _________________________________________________________________________ Date _________________________ Instructor _____________________________________________________________________ Score ________________________ Objective: After studying this chapter, you will be able to explain wheel alignment principles. 1. In reference to vehicles, what does the term alignment mean? _______________________________________________________________________________________________________Alignment means to position the four tires so they roll freely and evenly over the road surface. _______________________________________________________________________________________________________ _______________________________________________________________________________________________________ 2. What does correct alignment provide for a vehicle? _______________________________________________________________________________________________________Automobile safety, sure handling, maximum fuel economy, and long tire life. _______________________________________________________________________________________________________ _______________________________________________________________________________________________________ Wheel Alignment Principles 3. What is the main purpose of wheel alignment? _______________________________________________________________________________________________________To make the tires roll without scuffi ng, slipping, or dragging under all operating conditions. _______________________________________________________________________________________________________ _______________________________________________________________________________________________________ 4. Identify the six fundamental angles or specifi cations needed for proper wheel alignment. _______________________________________________________________________________________________________Any order: caster; camber; toe; steering axis inclination; toe-out on turns (turning radius); tracking _______________________________________________________________________________________________________(thrust line). _______________________________________________________________________________________________________ Caster 5. Steering wheel pull caused by the hump in the center _________________________________________________crown pull of the road is road _____. Copyright by The Goodheart-Willcox Co., Inc. 539 Ch80.indd 539 7/24/2013 1:01:24 PM 540 Modern Automotive Technology Workbook 6. Defi ne positive caster. _______________________________________________________________________________________________________Positive caster tilts the top of the steering knuckle toward the rear of the vehicle and helps keep the _______________________________________________________________________________________________________vehicle’s wheels traveling in a straight line. When you turn the wheels, it lifts the vehicle. Since this _______________________________________________________________________________________________________takes extra turning force, the wheels resist turning and try to return to the straight-ahead position. _______________________________________________________________________________________________________ _______________________________________________________________________________________________________ _______________________________________________________________________________________________________ 7. It is typical for positive caster to be recommended for _________________________________________________power vehicles with _____ steering. 8. Negative caster is recommended for vehicles with _________________________________________________manual _____ steering. 9. Explain how the directional control angle of caster is used to offset the effect of road crown. _______________________________________________________________________________________________________The right front wheel may be set with slightly more positive caster than the left. This counteracts the _______________________________________________________________________________________________________forces caused by the road crown, and the vehicle will travel straight ahead. _______________________________________________________________________________________________________ _______________________________________________________________________________________________________ _______________________________________________________________________________________________________ Camber 10. Defi ne camber. _______________________________________________________________________________________________________Camber is the inward or outward tilt of the wheel and tire assembly when viewed from the front of the _______________________________________________________________________________________________________vehicle. _______________________________________________________________________________________________________ 11. What are the three reasons for camber? _______________________________________________________________________________________________________Any order: to prevent tire wear on the outer or inner tread; to load the larger inner wheel bearing; to aid _______________________________________________________________________________________________________steering by placing vehicle weight on the inner end of the spindle. _______________________________________________________________________________________________________ _______________________________________________________________________________________________________ _______________________________________________________________________________________________________ 12. What is the difference between positive camber and negative camber? _______________________________________________________________________________________________________With positive camber, the tops of the wheels tilt outward when viewed from the front of the vehicle. _______________________________________________________________________________________________________With negative camber, the tops of the wheels tilt inward when viewed from the front. _______________________________________________________________________________________________________ _______________________________________________________________________________________________________ _______________________________________________________________________________________________________ Copyright by The Goodheart-Willcox Co., Inc. Ch80.indd 540 7/24/2013 1:01:25 PM Chapter 80 Wheel Alignment 541 Name _________________________________________________________________________ Toe 13. Toe is determined by the difference in _____ between _________________________________________________distance the front and rear of the left- and right-hand wheels. 14. Explain the difference between toe-in and toe-out. _______________________________________________________________________________________________________Toe-in is produced when the wheels are closer at the front than at the rear. Toe-in causes the wheels to _______________________________________________________________________________________________________point inward at the front. Toe-out results when the wheels are farther apart at the front than at the rear. _______________________________________________________________________________________________________Toe-out causes the front of the wheels to point away from each other. _______________________________________________________________________________________________________ _______________________________________________________________________________________________________ Steering Axis Inclination 15. Steering axis inclination is always a(n) _____ tilt, _________________________________________________inward regardless of whether the wheel tilts inward or outward. 16. How does steering axis inclination aid directional stability? _______________________________________________________________________________________________________By helping the steering wheel return to the straight-ahead position. _______________________________________________________________________________________________________ _______________________________________________________________________________________________________ Setback 17. Describe the difference between positive setback and negative setback. _______________________________________________________________________________________________________When setback is positive, the right wheel is farther back than the left wheel. Negative setback is present _______________________________________________________________________________________________________when the left wheel is farther back than the right wheel. _______________________________________________________________________________________________________ _______________________________________________________________________________________________________ 18. Excessive _____ will cause the vehicle to pull toward _________________________________________________setback the side with the wheel that is the farthest back. Toe-Out on Turns (Turning Radius) 19. Explain how toe-out on turns works. _______________________________________________________________________________________________________As the vehicle goes around a turn, the inside tire must travel in a smaller radius circle than the outside _______________________________________________________________________________________________________tire.