D Height Measurement

WARNING: This page is about a different car, the 2002 Cadillac Escalade EXT and 2002 Cadillac Escalade. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: There are no specified trim heights specifications on leaf spring vehicles because it is not an adjustable feature. The height of the suspension will depend on the option content of the vehicle as well as the aftermarket equipment that is placed on the vehicle. The measurements are used for comparison only and should be within 15 mm with the vehicle at curb and no accessories.

Place hand on the rear bumper and jounce the rear of the vehicle. Make sure that there is at least 38 mm (1.5 in) of movement while jouncing.
With the vehicle on a flat surface, lift upward on the rear bumper 38 mm (1.5 in).
Allow the vehicle to settle into position.
Measure the D height by measuring the distance between the bumper bracket and the top of the rear axle tube.

Fig 1: D Height Measurement
Courtesy of GENERAL MOTORS CORP.
Repeat the jouncing operation 2 more times for a total of 3 times.
Use the highest and lowest measurements to calculate the average height.
The true D height dimension number is the average of the high and the low measurements.
If these measurements are out of specifications, inspect for the following conditions:
- Sagging front suspension. Refer to Torsion Bar Replacement in FRONT SUSPENSION.
- Sagging rear leaf/coil springs Refer to LEAF SPRING or COIL SPRING .
- Worn rear suspension components, such as leaf spring bushings Refer to LEAF SPRING BUSHING .
- Improper tire inflation.
- Improper weight distribution.
- Collision damage.