Measuring the Z Dimension

Courtesy of GENERAL MOTORS COMPANY

Measurement Definitions 

The Z Height: The vertical distance from the bottom of the lower ball joint cup (1) to the bottom of the cradle (2) directly inward from the bottom of the ball joint cup.

Use the following procedures to measure the Z dimensions:

NOTE:

The left and right Z height differences should be no more than 10 mm (0.39 in).

1. Push the front bumper down a minimum of 25 mm (1 in) and release. Perform this step three times.
2. Measure and record the trim height per the "Measurement Definitions" above.
3. Lift the front bumper a minimum of 25 mm (1 in) and release. Perform this step three times.
4. Measure and record the trim height per the "Measurement Definitions" above.
5. The true Z height dimension is the average of the measurements taken in steps 2 and 4. Trim Height Specifications 
6. If these measurements are out of specifications, inspect for the following conditions:
   • Worn or damaged suspension components
   • Collision damage