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

Perform the following before to measuring the vehicles trim height:

Important: The left and right  Z height difference should be no more than  24 mm/.95 in.

1. Use the following procedure to measure the  Z Height;

1.1.	Lift the front bumper of the vehicle up to about 38 mm (1.5 in).

1.2.	Gently remove your hands and let the vehicle settle.

1.3.	Repeat this jouncing operation 2 more times for a total of 3 times.





1.4.	Measure and record the distance from the centerline (1) of the lower control arm bushing bolt (4) down to the machined edge of the steering knuckle (2) in order to obtain the Z height specifications.

1.5.	Repeat for the other side of the vehicle.

1.6.	Push the bumper of the vehicle down about 38 mm (1.5 in).

1.7.	Gently remove your hands and let the vehicle settle.

1.8.	Repeat the jouncing operation 2 more times for total of 3 times.

1.9.	Re-measure the Z height as in steps 1.4 and 1.5.

1.10.

The true Z height is the average of the measurements taken in steps 1.4 and 1.9. Compare this value to the published Z height specifications. Refer to Trim Height Specifications .

2. If any of these measurements are out of specifications, inspect for the following conditions:

•	Worn or damaged suspension components

•	Collision damage

Important: Cross vehicle D height should be within 12 mm (0.47 in) for vehicles equipped with coil springs and (0.31 in) for vehicles equipped with air suspension.

Important: On vehicles equipped with rear air suspension, verify that the ignition key is in the off position before jouncing the vehicle.

1. Lift the rear bumper of the vehicle up about 38 mm (1.5 in).
2. Gently remove your hands and let the vehicle settle.
3. Repeat this jouncing operation 2 more times for a total of 3 times.




Important: A D-height gage block can be used to determine the D--height position. Crate a D-height gage block using metal stock cut to 20 x 30 mm x the published D-height specifications. Refer to Trim Height Specifications . Use the block as a measuring device only.

4. Measure and record the D height by measuring the vertical distance (2) between the top surface of the axle and the side of the hole center on the jounce bumper reinforcement bracket.
5. Repeat for the other side of the vehicle.
6. Lift the rear bumper of the vehicle up about 38 mm (1.5 in).
7. Gently remove your hands and let the vehicle settle.
8. Repeat this jouncing operation 2 more times for a total of 3 times.
9. Re-measure the D height as in step 4.
10. The true D height is the average of the measurements from step 4 and step 9. Compare this value to the published D height specifications. Refer to Trim Height Specifications .
11. If any of these measurements are out of specifications, inspect for the following conditions. For vehicles equipped with coil springs:

•	Worn or damaged suspension components

•	Collision damage

12. For vehicles equipped with air suspension, refer to Air Suspension Description and Operation or Trim Height Inspection .