1. Automotive Alignment Angles
Camber
Caster
Front toe
Rear toe

2. Primary Alignment Angles
Front Camber
Rear Camber
Caster
Front Toe
Rear Toe
2 lines meet
to form an
Angle

3. 0 º ± 1 º -.5 º ± 1 º Camber Definition: Typical Range:
The inward or outward tilt of the top of the wheel as viewed from the front.
Typical Range:
Front camber -
Rear camber -
0 º ± 1 º
-.5 º ± 1 º

4. Zero Camber Wheel is vertical when viewed from the front
Measured as Zero degrees
Applicable to front and rear tires

5. Reasons to use at or near Zero Camber
Extremely wide tires
Positive offset rims
Extended Tire life

6. Positive Camber
Top of tire leans outboard at the top when viewed from the front
Measured in degrees
Primarily used on front wheels

7. Reasons to use Positive Camber
Places load inboard on spindle
Increases road isolation
Increases directional stability

8. Negative Camber
Top of tire leans inboard at the top when viewed from the front
Measured in degrees
Primarily used on rear wheels

9. Reasons to use Negative Camber
Places load outboard on spindle
Increased cornering ability
Increases road shock & component wear

10. Outside Shoulder Wear due to Excessive Positive Camber Angle

11. Camber may cause a Pull
Cross camber is the side-to-side difference in camber measurements
More than 1/2º difference side-to side may cause the vehicle to pull to the wheel with the most positive camber.

12. Excessive Cross Camber
Vehicle may pull to side of most positive camber

13. Camber Specifications
Preferred Specs Front = 0º Rear = -.40º
Tolerance Front = 1º Rear = .75º
Cross camber .70º

14. Exception to the rule

15. Caster
Front
The Forward or Rearward Tilt of the Steering Axis as viewed from the side
Typical Range
Typical tolerance ± 1º
1º to 6 º positive

16. Steering Axis Line drawn between the two pivot points
of the steering knuckle

17. Zero Caster
Steering Axis is vertical as viewed from the side and measured as 0º

18. Negative Caster
Forward tilt of the Steering Axis as viewed from the side and measured in degrees
Front

19. Positive Caster
Rearward tilt of the Steering Axis as viewed from the side and measured in degrees
Front

20. Benefits of Positive Caster
Helps to return wheels to straight ahead after being steered
Helps to maintain directional stability
Weight must be picked up as spindle turns downward ….

21. Negative effects of Excessive Positive Caster
Excessive steering effort & road shock
Shimmy due to excessive speed of wheels returning to center
Steering damper used to control speed of steered wheels returning to center
Dampner

22. Caster Measurement
The amount of camber change during a 10° steer to the left & right
spindle arc

23. Tire wear factor of Caster
Tires may show wear on both outer edges due to camber roll.
Camber roll - the change in camber during a turn due to caster
The amount of camber change is relative to the amount of positive caster

24. Camber Roll Left spindle down - right spindle up
Left spindle up - right spindle down

25. Caster may cause a Pull
Cross caster is the side-to-side difference in caster measurements
More than 1/2º difference side-to side may cause the vehicle to pull to the wheel with the least positive caster.

26. Cross Caster Vehicle may pull to side of least positive caster
Cross Caster = Left caster minus right caster
2º caster
1º caster
Vehicle may pull to side of least positive caster

27. Caster Specification Preferred Spec Front 3.80º Rear n/a
Tolerance Front 1º
Cross caster .85º

28. Review Purpose of Alignment Angles Camber Definitions
Measurement method
Specification
Tire wear factor
Pull factor

29. Review Caster Definitions Measurement method Specification
Tire wear factor
Pull factor

30. Front Toe Angles Incorrect front toe angles may cause:
outside shoulder wear
inside shoulder wear
wandering
darting
Total toe changes as the speed of the vehicle increases

31. Total Toe
The difference in the distance measured between lines drawn through the center of tires on the same axle.
Measurements are taken at the front and rear of the tires.

32. Zero Total Toe
80”
Equal distance when measured across the front and the rear of tires on the same axle.

33. Toe-In Measured distance is shorter between the front of the tires.
front = 79 in.
rear = 80 in.
79”
80”
Total toe-in = 1 in.

34. Excessive Toe-In Tire Wear
Outside
shoulder
wear
Center
of car

35. Toe-Out Measured distance is shorter between the front of the tires.
front = 80 in.
rear = 79 in.
80”
79”
Total toe-out = 1 in.

36. Excessive Toe-Out Tire Wear
Inside
shoulder
wear
Center
of car

37. Total Toe Angle
The Total toe may also be displayed as an angle and expressed in degrees.
Total
toe angle

38. Total Toe Specification
Negative number indicates Toe-Out
Positive number indicates Toe-In

39. Individual Toe
Front individual toe is responsible for steering wheel position

40. Front Individual Toe
Left Front
Individual
toe angle
Centerline
toe
angle
Angle formed by the intersection of the geometric centerline and a line drawn through the center of the wheel

41. Rear Individual Toe Rear individual toe is responsible for: tire wear
thrust angle
vehicle tracking

42. Rear Tire Wear Patterns
Toe-In
Outside shoulder
Toe-Out
Inside shoulder
Diagonal Wipe
a condition that may result on rear tires with excessive toe
Diagonal Wipe

43. Geometric Centerline
A line drawn between the midpoint of both the front and rear axles.

44. Thrust Line
The bisector of rear total toe. Also described as the direction the rear wheels are pushing the vehicle.

45. Thrust Angle - formed by the intersection of the geometric centerline and the thrustline ( a line bisecting rear total toe )
Thrustline
Thrust angle
Geometric Centerline

46. Positive & Negative Thrust Angle+
Positive Thrust Angle is to the Right
Negative Thrust Angle is to the Left -

47. Dog Tracking
A visible dog track condition will be present, if the thrust angle is excessive.

48. Review Front total toe is responsible for tire wear factors:
excessive toe-in =
outside shoulder wear
darting
excessive toe-out =
inside shoulder wear
wandering
Front individual toe is responsible for steering wheel position

49. Thrustline: the direction the rear wheels are pointing the vehicle
bisector of the total toe angle
Thrust Angle: the angle formed by the intersection of the geometric centerline and the thrustline
Rear tire wear patterns:
outside or inside shoulder wear
diagonal wipe if the toe angle is extreme
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