AXIS4000
W
HEEL
A
LIGNMENT
S
YSTEM
HAWEKA Wheel Alignment –AXIS4000
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2.2 Measurement sizes for wheel alignment
Straight running
One of the reference sizes for recording measurement values is the
chassis centre-line. Wheel alignment is an aid for aligning the front
wheels with the same individual tracking from the chassis centre-line.
Total toe
This is defined in terms of toe-in and toe-out. The toe-in is the value
by which the front or rear wheel points inward toward each other at
the front. The toe-in is expressed as a positive value.
If the wheels point outward, this is referred to as toe-out, which is
expressed as a negative value. A correct toe-in or toe-out alignment
ensures that the wheels run parallel when the vehicle is in motion.
Camber
If the wheel is angled outward when the vehicle is viewed from the
front or rear, this is referred to as positive camber (B); if it is angled
inward, this is called negative camber (C). The effect of the camber
can be compared to a cone, which always has a tendency to roll to-
ward the narrowed end (A). Consequently, wheels which both have a
positive camber have a tendency to roll away from each other, while
wheels with negative camber roll towards each other.
Relative steering angle
The relative steering angle is the difference in the angles between the
front wheels and the vehicle centre-line when the steering wheel is
turned. The angle (A) must be the same when steering to the right or
left, taking the manufacturer’s tolerances into account. The meas-
urement is carried out at an angle of 20° of the wheel on the inside of
the curve.
Inclination
Inclination is the angle of the king pin from the vertical to the centre-
line of the vehicle (A). For vehicles with ball pins instead of king pins,
the imaginary line through the steering rotation axis of the ball pins is
used for measurement.
Inclination and camber together form the included angle (B). The axle
stub must be checked for distortion or cracks if this deviates severely
from the nominal value.
Castor
The castor designates the angle of the king pin to the vertical either to
the front or rear. The castor angle affects the directional steering sta-
bility. Positive castor: high steering and holding forces
Negative castor: poor steering return.
