Chrysler PT Cruiser Service & Repair Manual page 82

2 - 54 WHEEL ALIGNMENT
WHEEL ALIGNMENT (Continued)
TOE-OUT ON TURNS
Toe-out on turns is the relative positioning of the
front wheels while steering through a turn (Fig. 4).
This compensates for each front wheel's turning
radius. As the vehicle encounters a turn, the out-
board wheel must travel in a larger radius circle
than the inboard wheel. The steering system is
designed to make each wheel follow its particular
radius circle. To accomplish this, the front wheels
must progressively toe outward as the steering is
turned from center. This eliminates tire scrubbing
and undue tire wear when steering a vehicle through
a turn.
Fig. 4 Toe-Out On Turns
1 - TOE-OUT ON TURNS
DYNAMIC TOE PATTERN
Dynamic toe pattern is the inward and outward toe
movement of the front and rear tires through the
suspension's jounce and rebound travel. As the vehi-
cle's suspension moves up and down, the toe pattern
varies. Toe pattern is critical in controlling the direc-
tional stability of the vehicle while in motion. Front
and rear dynamic toe pattern is preset by the factory
at the time the vehicle is assembled.
It is not necessary to check or adjust front or rear
dynamic toe pattern when doing a normal wheel
alignment. The only time dynamic toe pattern needs
to be checked or adjusted is if the frame of the vehi-
cle has been damaged.
STEERING AXIS INCLINATION (S.A.I.)
Steering axis inclination is the angle between a
true vertical line starting at the center of the tire at
the road contact point and a line drawn through the
center of the upper ball joint (or strut) and the lower
ball joint (Fig. 5). S.A.I. is built into the vehicle and
is not an adjustable angle. If S.A.I. is not within
specifications, a bent or damaged suspension compo-
nent may be the cause.
Fig. 5 S.A.I. and I.A.
1 - S.A.I.
2 - CAMBER
3 - I.A.
INCLUDED ANGLE (I.A.)
Included angle is the sum of the S.A.I. angle plus
or minus the camber angle, depending on whether or
not the wheel has positive or negative camber (Fig.
5). If camber is positive, add the camber angle to the
S.A.I angle. If camber is negative, subtract the cam-
ber angle from the S.A.I. angle. Included angle is not
adjustable, but can be used to diagnose a frame mis-
alignment or bent suspension component (spindle,
strut).
PT