Alignment Fundamentals Part One

1
Alignment Fundamentals Part One
2
Suspension Systems

• Designed to
• provide satisfactory vehicle control
• acceptable driver effort
• Maintains directional stability
• on various road surfaces
• all types of weather
• loaded and unloaded
• towing

3
Road Variables

• Road Crown
• Bumps Pot Holes
• Crosswinds Cross winds created by other
  vehicles
• Road surfaces
• Side forces
• Drive axle forces
• Suspension part movement

4
Rear Wheel Alignment Vehicle Tracking

• Thrust Line Imaginary line _at_ 90 degree angle to
  the centerline of the rear wheels
• Rear Wheel Offset axle asm out of position, not
  parallel to centerline

5
Improper Thrust Angle
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Wheel Base

• The distance between the center of the front
  rear wheels

7
Tracking

• Position of the rear wheels in relationship to
  the front

8
Ride Height

• The distance between the frame the ground. If
  distance varied over ¼ between sides, handling
  can be affected.

9
Camber Fundamentals

• Inward/outward tilt of wheel from true vertical.
  
• Vehicle will pull to side most positive.
• Affects tire wear.

10
Camber Fundamentals

• Negative Camber Positive Camber

11
Jounce Rebound

• Jounce - Upward wheel movement
• Rebound Downward wheel movement

12
Caster Fundamentals

• Tilt of a line that intersects the lower and
  upper ball joints (strut mount) in relation to
  true vertical

13
Caster Fundamentals
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Positive Caster

• Helps return to straight ahead position
• Increases steering effort, the wheels try to stay
  straight
• Pos caster helps maintain directional stability
• Too much affects steering, rapid wheel return
• Pulls to side with the most pos caster.

15
Negative Caster

• Decreases directional stability
• Reduces steering effort

16
Tire Wear

• Caster has effect on tire wear