Suspension System: Other Chrysler Pacifica CS

CAMBER

Camber is the inward or outward tilt of the top of the tire and wheel assembly. (Scheme 72) Camber is measured in degrees of angle relative to a true vertical line. Camber is a tire wearing angle.

1. Excessive negative camber will cause tread wear at the inside of the tire.
2. Excessive positive camber will cause tread wear on the outside of the tire.

Scheme 72

CROSS CAMBER

Cross camber is the difference between left and right camber. To achieve the cross camber reading, subtract the right side camber reading from the left. For example, if the left camber is +0.3° and the right camber is 0.0°, the cross camber would be +0.3°.

CASTER

Caster is the forward or rearward tilt of the steering knuckle in reference to the position of the upper and lower ball joints. Caster is measured in degrees of angle relative to a true vertical center line. This line is viewed from the side of the tire and wheel assembly. (Scheme 73)

1. Forward tilt (upper ball joint ahead of lower) results in a negative caster angle.
2. Rearward tilt (upper ball joint trailing lower) results in a positive caster angle.

Although caster does not affect tire wear, a caster imbalance between the two front wheels may cause the vehicle to lead to the side with the least positive caster.

Scheme 73

CROSS CASTER

Cross caster is the difference between left and right caster.

TOE

Toe is the inward or outward angle of the wheels as viewed from above the vehicle. (Scheme 74)

1. Toe-in is produced when the front edges of the wheels on the same axle are closer together than the rear edges.
2. Toe-out is produced when the front edges of the wheels on the same axle are farther apart than the rear edges.

Toe-in and toe-out can occur at the front wheels and the rear wheels.

Toe is measured in degrees or inches. The measurement identifies the amount that the front of the wheels point inward (toe-in) or outward (toe-out). Toe is measured at the spindle height. Zero toe means the front and rear edges of the wheels on the same axle are equally distant.

Scheme 74

TOE-OUT ON TURNS

Toe-out on turns is the relative positioning of the front wheels while steering through a turn. (Scheme 75) This compensates for each front wheel's turning radius. As the vehicle encounters a turn, the outboard 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.

Scheme 75

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 vehicle's suspension moves up and down, the toe pattern varies. Toe pattern is critical in controlling the directional 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 vehicle 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. (Scheme 76) 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 component may be the cause.

Scheme 76

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. (Scheme 76) If camber is positive, add the camber angle to the S.A.I. angle. If camber is negative, subtract the camber angle from the S.A.I. angle. Included angle is not adjustable, but can be used to diagnose a frame misalignment or bent suspension component (spindle, strut).

THRUST ANGLE

Thrust angle is the averaged direction the rear wheels are pointing in relation to the vehicle's center line. (Scheme 77) The presence of negative or positive thrust angle causes the rear tires to track improperly to the left or right of the front tires (dog tracking).

1. Negative thrust angle means the rear tires are tracking to the left of the front tires.
2. Positive thrust angle means the rear tires are tracking to the right of the front tires.

Scheme 77

Improper tracking can cause undue tire wear, a lead or pull and a crooked steering wheel. Excessive thrust angle can usually be corrected by adjusting the rear wheel toe so that each wheel has one-half of the total toe measurement.

CAMBER AND CASTER

Camber and caster settings on this vehicle are determined at the time the vehicle is designed, by the location of the vehicle's suspension components. This is referred to as NET BUILD. The result is no required adjustment of camber and caster after the vehicle is built or when servicing the suspension components. Thus, when performing a wheel alignment, caster and camber are not normally considered adjustable angles. Camber and caster should be checked to ensure they meet vehicle specifications.

If front camber is found not to meet alignment specifications, it can be adjusted using an available camber adjustment bolt package. Before installing a camber adjustment bolt package on a vehicle found to be outside the specifications, inspect the suspension components for any signs of damage or bending.

If front camber readings are not within specifications, use the following procedure to install a camber adjustment bolt package, then adjust front camber.

1. Center the steering wheel and lock in place using a steering wheel clamp. NOTE: When performing the toe adjustment procedure, set rear toe to specifications before setting front toe.
2. Loosen the cam bolt nut securing the toe link to the rear crossmember just enough to rotate the cam bolt. see scheme 96 1 - WASHER 2 - CAM WASHER (TOE ADJUSTMENT) 3 - REAR OF REAR CROSSMEMBER 4 - TOE LINK 5 - NUT 6 - FLAT ON CAM BOLT
3. Rotate the cam bolt head on the opposite side (front) of the crossmember in either direction until the preferred specification is obtained. see scheme 97 «(Refer to SUSPENSION/WHEEL ALIGNMENT - SPECIFICATIONS)»(ref-245426-S03297586692006110200000) 1 - CAM BOLT (TOE ADJUSTMENT) 2 - FRONT OF REAR CROSSMEMBER
4. While holding the cam bolt from turning, tighten the cam bolt nut to specifications.
5. Adjust rear toe on opposite side of vehicle using above procedure as necessary.
6. Once rear toe is set, proceed to FRONT TOE to set the vehicle's front toe.
7. Loosen jam nut at inner-to-outer tie rod connection. see scheme 98
8. Grasp inner tie rod at serrations and rotate as necessary to adjust front toe to preferred toe specification. see scheme 98 «(Refer to SUSPENSION/WHEEL ALIGNMENT - SPECIFICATIONS)»(ref-245426-S03297586692006110200000) 1 - STEERING KNUCKLE 2 - JAM NUT (TIE ROD ADJUSTMENT) 3 - INNER TIE ROD SERRATIONS 4 - OUTER TIE ROD 5 - NUT
9. Tighten tie rod jam nut to specifications.
10. Make sure inner tie rod-to-steering gear boot is not twisted, then reinstall boot clamp at inner tie rod.
11. Adjust front toe on opposite side of vehicle using above procedure as necessary.
12. Remove steering wheel clamp.
13. Remove alignment equipment.
14. Road test vehicle to verify steering wheel is straight and vehicle does not wander or pull.

STANDARD PROCEDURE - CURB HEIGHT MEASUREMENT

The wheel alignment is to be checked and all alignment adjustments made with the vehicle at its required curb height specification.

Vehicle height is to be checked with the vehicle on a flat, level surface, preferably a vehicle alignment rack. The tires are to be inflated to the recommended pressure. All tires are to be the same size as standard equipment. Vehicle height is checked with the fuel tank full of fuel, and no passenger or luggage compartment load.

Vehicle height is not adjustable. If the measurement is not within specifications, inspect the vehicle for bent or weak suspension components. Compare the parts tag on the suspect coil spring(s) to the parts book and the vehicle sales code, checking for a match. Once removed from the vehicle, compare the coil spring height to a correct new or known good coil spring. The heights should vary if the suspect spring is weak.

1. Measure from the inboard edge of the wheel opening fender lip directly above the wheel center (spindle), to the floor or alignment rack surface.
2. When measuring, the maximum left-to-right differential is not to exceed 12.5 mm (0.5 in.).
3. Compare the measurements to the specifications listed in the following Curb Height Specifications chart.

CURB HEIGHT SPECIFICATIONS