Caster & Camber
Pre-Alignment Inspection
Fig. 1 Wheel Alignment Measurements:
Before starting a front wheel alignment, the following inspection and necessary corrections must be completed.
1. Check and inflate all the tires with the same recommended air pressure. All the tires should be the same size, in good condition and have approximately the same tread wear. If the tread wear is abnormal, note the type of wear. This will aid in fault diagnosis.
2. Inspect and adjust (if necessary) the front wheel bearings.
3. Inspect the front wheels for evidence of excessive radial and lateral runout.
4. Inspect the wheels for evidence of unbalance. Both static and dynamic unbalance can affect the vehicle steering.
5. Inspect the ball studs and all the steering linkage pivot locations for excessive looseness.
6. Inspect the shock absorbers for leaks. Jounce the vehicle to determine if the shock absorbers dampen vehicle motion properly.
7. Inspect the steering gear for roughness, binding or a sticking condition. Adjust/repair as necessary.
8. Inspect the rear springs for damage.
Inspect the U-bolt nuts for correct tightness.
Note: To aid in ensuring accurate measurements, the vehicle should be jounced. Grasp each bumper at the center (rear bumper first) and vigorously jounce the vehicle up and down several times. Always release the bumper when it's at the down position. During jouncing, it is recommended that the front bumper elevation (vertical movement) should raise to at least 4 inches above the normal height. Jounce the rear and front ends of the vehicle an equal number of times.
Wheel Alignment Measurements/Adjustments
The front wheel alignment positions must be set to the specified limits to prevent abnormal tire tread wear, and to ensure steering ease and safe operation of the vehicle.
Note: The equipment manufacturer's recommendations for use of their equipment should always be followed. All damaged front suspension system components should be replaced. Do not attempt to straighten any bent component.
The correct wheel camber (vertical tilt) angle is factory preset at positive one degree (+1°).
Camber cannot be altered by adjustment.
CAUTION: DO NOT ATTEMPT TO ADJUST THE CAMBER ANGLE BY HEATING OR BENDING THE AXLE OR ANY SUSPENSION COMPONENT. IF CAMBER ANGLE IS INCORRECT, THE COMPONENT(S) CAUSING AN INCORRECT ANGLE MUST BE REPLACED.
1. It is important that the camber (vertical tilt) angle be the same for both front wheels.
2. The camber angle should be measured with accurate wheel alignment equipment.
The acceptable range is + 1/2° to + 1 1/2°.
Refer to the Specifications chart.
A satisfactory test for assurance can be made by road testing the vehicle and observing the steering wheel return-to-center position.
Note: Before road testing, check and correct the tire inflation pressures. Inflate both of the front tires with exactly the same pressure.
During the road test, make vehicle turns to both the left and right. If the steering wheel returns toward the center position unassisted, the caster angle is correct. However, if the steering wheel does not return toward the center position unassisted, an incorrect caster angle is probable.
1. The caster angle is factory preset at positive two degrees ( + 2°).
The acceptable range is + 1/2° to + 3 1/2°.
2. The caster angle should be measured with accurate wheel alignment equipment.
3. Caster angle can be adjusted by installing tapered shims between the front axle pads and the spring brackets.
The caster angle should be adjusted as near as possible to the preferred angle.
4. Record the caster measurement before removing the original shims from the spring pads.
5. The caster should be the same at both sides of the vehicle.
Refer to the Specifications chart. Specifications