Wheel Alignment System: Other Cadillac STS I

Trim Height Measurements

Trim height is a predetermined measurement relating to vehicle ride height. Incorrect trim heights can cause bottoming out over bumps, damage to the suspension components and symptoms similar to wheel alignment problems. Check the trim heights when diagnosing suspension concerns and before checking the wheel alignment.

Perform the following before measuring the trim heights

1. Set the tire pressures to the pressure shown on the certification label. Refer to «Label - Vehicle Certification, Tire Place Card, Anti-Theft and Service Parts ID»(ref-197567-S13116101512005101200000) in General Information.
2. Check the fuel level. Add additional weight if necessary to simulate a full tank.
3. Make sure the rear compartment is empty except for the spare tire.
4. Make sure the vehicle is on a level surface, such as an alignment rack.
5. Close the doors.
6. Close the hood.
7. All dimensions are measured vertical to the ground. Trim heights should be within 13 mm (0.5 in) to be considered correct.

Z Height Measurement

The Z height dimension measurement determines the proper ride height for the front end of the vehicle. There is no adjustment procedure. Repair may require replacement of suspension components.

1. Lift the front bumper of the vehicle up about 38 mm (1.5 in).
2. Gently remove your hands. Let the vehicle settle.
3. Repeat this operation for a total of 3 times.
4. Measure from the pivot bolt center line down to the lower corner of the lower ball joint in order to obtain the Z height measurement.
5. Push the front bumper of the vehicle down about 38 mm (1.5 in).
6. Gently remove your hands.
7. Allow the vehicle to settle into position.
8. Repeat the jouncing operation 2 more times for a total of 3 times.
9. Measure the Z dimension.
10. The true Z height dimension number is the average of the high and the low measurements. Refer to «Trim Height Specifications»(ref-197577-S34217746232005101200000) .

D Height Measurement

The D height dimension measurement determines the proper rear end ride height. There is no adjustment procedure. Repair may require replacement of suspension components.

1. With the vehicle on a flat surface, lift upward on the rear bumper 38 mm (1.5 in).
2. Gently remove your hands. Allow the vehicle to settle into position.
3. Repeat the jouncing operation 2 more times for a total of 3 times.
4. Measure the D height by measuring the distance between the bumper bracket and the top of the rear axle tube.
5. Push the rear bumper downward to 38 mm (1.5 in).
6. Gently remove your hands. Allow the vehicle to settle into position.
7. Repeat the jouncing operation 2 more times for a total of 3 times.
8. Measure the D height dimension.
9. The true D height dimension number is the average of the high and the low measurements. Refer to «Trim Height Specifications»(ref-197577-S34217746232005101200000) .
10. If these measurements are out of specifications, inspect for the following conditions: Improper weight distribution Collision damage Worn or damaged suspension components

Tools Required

J 45845 Caster and Camber Adjusting Tool. See Special Tools .

1. Install J 45845 to the lower control arm and the frame. See «Special Tools»(ref-197577-S12423058042005101200000) .
2. Loosen the lower control arm to frame bolt.
3. Adjust the camber angle by turning the turnbuckle on J 45845 until the specifications have been met. See «Special Tools»(ref-197577-S12423058042005101200000) . Tighten: Tighten the bolt to 135 N.m (96 lb ft).
4. Verify that the camber is still with specifications. Refer to «Wheel Alignment Specifications»(ref-197577-S38659686492005101200000) .
5. Adjust the rear toe. Refer to «Rear Toe Adjustment»(ref-197577-S12451222972005101200000) .

J 45845 Caster and Camber Adjusting Tool. See Special Tools .

The caster and camber adjustments are made by loosening the lower control arm adjustment bolts and repositioning the lower control arm.

1. For an accurate reading, do not push or pull on the tires during the alignment process.
2. Determine the caster angle (2, 3).
3. Determine the camber angle (2, 3).
4. Install the J 45845 to the lower control arm and the frame. See «Special Tools»(ref-197577-S12423058042005101200000) .
5. Loosen the lower control arm adjustment nuts. NOTE: Refer to «Fastener Notice»(ref-197542-S12062241132005101200000) in Cautions and Notices.
6. Adjust the caster and the camber angle by repositioning the lower control arm until the specifications have been met. When the adjustments are complete, hold the lower control arm in position so that the specifications do not change while tightening the lower control arm adjustment bolts. Tighten: Tighten the lower control arm adjustment bolts to 135 N.m (96 lb ft).
7. Verify that the caster and the camber are still within specifications. Refer to «Wheel Alignment Specifications»(ref-197577-S38659686492005101200000) . When the caster and camber are within specifications, adjust the toe. Refer to «Front Toe Adjustment»(ref-197577-S32656509152005101200000) .