Wheel
Alignment
Why Wheel Alignment is Important
When the front wheels of a vehicle are correctly
aligned, they will roll without dragging or slipping and with a minimum of
steering effort. Tires wear evenly and less strain is placed on
front suspension parts. All this contributes to greater driving
safety.
Five angles are involved in proper wheel
alignment: Caster, camber, toe-in, toe-out on turns and steering
axis inclination. Actually, six measurements are involved, since
most manufacturers specify the checking of front suspension height before
making any adjustments. Caster, camber, toe-out on turns and
steering inclination are measured in degrees and minutes: Toe-in and
suspension height (some models) are adjustable; toe-out on turns and
steering axis inclination are factory set and non-adjustable. On
some vehicles, caster and camber are not adjustable.
Toe-In
The wheels on the same axle are closer together in
the front than they are in the rear. When toe-in is excessive, the
tire wear shows feather edges.
Toe-Out
The wheels on the same axle are closer together in
the rear than they are in the front. Tire wear shows feathered
edges.
Camber
This designates the tilt of the wheel.
Positive camber is when wheels are closer together at point of road
contact. Negative camber is when wheels are closer together at top.
Too much camber results in excessive wear on one side of tyre.
Caster
This is the backward tilt of the axle or
inclination of the kingpin at the top. Too little caster causes the wheel
to wander or weave-result, spotty wear. Excessive caster may cause wheel
"fight" or shimmy wear. Unequal caster causes wheel to pull to
one side, resulting in excessive and uneven wear.
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