Jeep 1997 Grand Cherokee Service Manual page 27

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ALIGNMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
FRONT SUSPENSION . . . . . . . . . . . . . . . . . . . . . 4
GENERAL INFORMATION
WHEEL ALIGNMENT . . . . . . . . . . . . . . . . . . . . . 1
DIAGNOSIS AND TESTING
PRE-ALIGNMENT INSPECTION . . . . . . . . . . . . . 3
GENERAL INFORMATION
WHEEL ALIGNMENT
Wheel alignment involves the correct positioning of
the wheels in relation to the vehicle. The positioning
is accomplished through suspension and steering
linkage adjustments. An alignment is considered
essential for efficient steering, good directional stabil-
ity and to minimize tire wear. The most important
measurements of an alignment are caster, camber
and toe position (Fig. 1).
• CASTER is the forward or rearward tilt of the
steering knuckle from vertical. Tilting the top of the
knuckle rearward provides positive caster. Tilting the
top of the knuckle forward provides negative caster.
Caster is a directional stability angle. This angle
enables the front wheels to return to a straight
ahead position after turns.
• CAMBER is the inward or outward tilt of the
wheel relative to the center of the vehicle. Tilting the
top of the wheel inward provides negative camber.
Tilting the top of the wheel outward provides positive
camber. Incorrect camber will cause wear on the
inside or outside edge of the tire. The angle is not
adjustable, the damaged component(s) must be
replaced to correct mis-alignment.
SUSPENSION
CONTENTS
page
REAR SUSPENSION . . . . . . . . . . . . . . . . . . . . . 11
ALIGNMENT
INDEX
page
SERVICE PROCEDURES
SPECIFICATIONS
ALIGNMENT
•
WHEEL TOE POSITION is the difference
between the leading inside edges and trailing inside
edges of the front tires. Incorrect wheel toe position
is the most common cause of unstable steering and
uneven tire wear. The wheel toe position is the final
front wheel alignment adjustment.
• STEERING AXIS INCLINATION ANGLE is
measured in degrees and is the angle that the steer-
ing knuckles are tilted. The inclination angle has a
fixed relationship with the camber angle. It will not
change except when a spindle or ball stud is dam-
aged or bent. The angle is not adjustable, the dam-
aged component(s) must be replaced to correct mis-
alignment.
• THRUST ANGLE is the angle of the rear axle
relative to the centerline of the vehicle. Incorrect
thrust angle can cause off-center steering and exces-
sive tire wear. This angle is not adjustable, the dam-
aged component(s) must be replaced to correct mis-
alignment.
CAUTION: Do not attempt to modify any suspen-
sion or steering component by heating and bend-
ing.
SUSPENSION
. . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2 - 1
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