Tire Wear Due to Improper Toe Settings
Toe is the most critical alignment setting for steer axle tire wear. It is measured in inches, millimeters or degrees.
Total Toe is the angle formed by two horizontal
lines through the planes of two wheels. Toe-in is
when the horizontal lines intersect in front of the
vehicle; Toe-out is when the horizontal lines
intersect behind the wheels.
Individual Toe is the angle drawn by a line
drawn through a plane of one wheel referenced
to the thrust line of the vehicle. Toe-in is when
the horizontal lines intersect in front of the
wheel. Toe-out is when the lines intersect
behind the wheel.
| Results of excessive toe is wear on the
leading edge of the tire.
Excessive toe-in wears the outside of the tire.
Excessive toe-out wears the inside of the tire.
Tire Wear Due to Improper
Camber is the angle formed by the inward or
outward tilt of the wheel referenced to a vertical
line. This angle is measured in degrees.
Camber is positive when the wheel is tilted
outward at the top and is negative when the
wheel is tilted inward at the top.
Tire wear from excessive camber: Wear
from positive camber is on the outside shoulder
of the tire; with negative camber, wear is on the
Caster: A Factor in
Caster is the forward or rearward tilt of the
steering axis in reference to a vertical line. The
angle is measured in degrees. Caster is positive
when the top of the steering axis is tilted rearward
and is negative when the tilt is forward. Caster is
usually a factor in vehicle handling, but can affect
tire wear. Proper caster is important for directional
stability and returnability. Improper caster can
cause shimmy, excessive steering effort, pulling
and shoulder wear on the steer tires.
Turning angle is the difference in the angles of
the front wheels in a turn. This measurement is an
aid in diagnosing steering problems and irregular
tire wear. Improper turning angle may cause
scuffing, leading to excessive tire wear.