Trim Height Inspection
Trim Height Inspection
Trim Height Measurement
Trim height is a predetermined measurement relating to vehicle ride height. Incorrect trim heights can cause the vehicle to bottom 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:
* Set the tire pressure to the specifications shown on the certification label. Refer to Vehicle Certification, Tire Placard, Anti-Theft, and Service Parts ID Label (Application and ID).
* Check the fuel level. Add additional weight if necessary to simulate a full tank.
* Make sure the passenger and rear compartments are empty, except tor the spare tire.
* Make sure the vehicle is on a flat and level surface, such as an alignment rack.
* Check that all the vehicle doors are securely closed.
* Check that the vehicle hood and rear deck lids are securely closed.
* Check for installed after market accessories or modifications that could affect trim height measurement.
Measuring the P and R Dimension
Important: All dimensions are measured vertical to the ground. Trim height should be within ±10 mm (±0.39 in) to be considered correct.
Use the following procedure to check the P and R dimensions:
1. Lift the front bumper of the vehicle up about 38 mm (1.5 in).
2. Gently remove your hands and let the vehicle settle.
3. Repeat this operation 2 more times for a total of 3.
4. P height is measured vertically from the ground to the bottom lip of the wheel opening through the centerline of the front wheel.
5. Push the front bumper of the vehicle down about 38 mm (1.5 in).
6. Gently remove your hands and let the vehicle settle down.
7. Repeat this operation 2 more times for a total of 3.
8. Measure the P height as in step 4.
9. The true P height measurement is the average of the measurements taken in step 4 and 8.
10. Repeat the above steps on the rear of the vehicle for the R heights
Measuring the Z Dimension
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.
Use the following procedure to check the Z height dimension:
1. Using your hands, lift the front bumper approximately 38 mm (1.59 in).
2. Gently remove your hands and allow the vehicle to settle.
3. Repeat the jouncing operation a total of 3 times.
4. You will need 2 measurements to compute the Z height. Measurement 1 should be taken from the bottom edge of the support flange (X) to the ground line. Measurement 2 should be taken from the bottom edge of the lowest point of the ball stud (Y) to the ground line. Subtract measurement 2 (Y) from measurement 1 (X). This will give you your Z height dimension.
5. Using your hands, jounce the front of the vehicle downward approximately 38 mm (1.59 in).
6. Gently remove your hands and allow the vehicle to settle.
7. Repeat the jouncing operation a total of 3 times.
8. Measure the Z height dimension.
9. The true Z height dimension number is the average of the high and the low measurements. Refer to Trim Height Specifications (Trim Height Specifications).
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.
Use the following procedure to check the D dimension:
1. With the vehicle on a flat level surface, lift upward on the rear bumper 38 mm (1.59 in).
2. Gently remove your hands and allow the vehicle to settle.
3. Repeat the jouncing operation 2 more times.
4. Measure the vertical distance from the bottom surface of the floor pan to the top surface of the control arm flange.
5. Repeat this task for the other side of the vehicle.
6. Using your hands, jounce the front of the vehicle downward approximately 38 mm (1.59 in).
7. Gently remove your hands and allow the vehicle to settle.
8. Repeat the jouncing operation 2 more times.
9. Measure the D height dimension.
10. The true D height dimension number is the average of the high and the low measurements. Refer to Trim Height Specifications (Trim Height Specifications).
11. If these measurements are out of specifications, inspect for the following conditions:
* Worn or damaged suspension components
* Collision damage