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.
   Fig 1: Checking Z Height Adjustment

   Courtesy of GENERAL MOTORS CORP.
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  .
10. If these measurements are out of specifications, Inspect for the following conditions:
    • Sagging front suspension Refer to FRONT COIL SPRINGS REPLACEMENT or TORSION BAR REPLACEMENT .
    • Sagging rear leaf/coil springs. Refer to LEAF SPRING REPLACEMENT .
    • Worn rear suspension components, such as leaf spring bushings. Refer to SPRING BUSHING REPLACEMENT .
    • Improper tire inflation
    • Improper weight distribution
    • Collision damage