GM Service Manual Online
For 1990-2009 cars only

Z Height Measurement

Rear Wheel Drive

In order to determine the Z height measurement, use the following procedure:

  1. Lift the front bumper of the vehicle up about 38 mm (1.5 in).
  2. Gently remove your hands. Allow the vehicle to settle.
  3. Repeat the previous two steps two more times, for a total of three times.

  4. Object Number: 95  Size: SH
  5. Measure from the lower control arm pivot bolt center line down to the lower corner of the steering knuckle in order to obtain the Z height dimension.
  6. Push the front bumper of the vehicle down about 38 mm (1.5 in).
  7. Gently remove your hands. Allow the vehicle to settle.
  8. Repeat the previous two steps two more times, for a total of three times.
  9. Measure from the lower control arm pivot bolt center line down to the lower corner of the steering knuckle in order to obtain the Z height dimension.
  10. Find the average of the high measurements and the low measurements in order to determine the Z height dimension.

Automatic Four-Wheel Drive

In order to determine the Z height measurement, use the following procedure:

  1. Lift the front bumper of the vehicle up about 38 mm (1.5 in).
  2. Gently remove your hands. Allow the vehicle to settle.
  3. Repeat the previous two steps two more times, for a total of three times.

  4. Object Number: 156339  Size: SH
  5. Measure from the lower control arm (3) pivot bolt center line (2) down to the lower corner (5) of the steering knuckle (1) in order to obtain the Z height dimension (4).
  6. Push the front bumper of the vehicle down about 38 mm (1.5 in).
  7. Gently remove your hands. Allow the vehicle to settle.
  8. Repeat the previous two steps two more times, for a total of three times.
  9. Measure from the lower control arm (3) pivot bolt center line (2) down to the lower corner (5) of the steering knuckle (1) in order to obtain the Z height dimension (4).
  10. Find the average of the high measurements and the low measurements in order to determine the Z height dimension.

D Height Measurement

In order to determine the D height measurement, use the following procedure:

  1. Lift the rear bumper of the vehicle up about 38 mm (1.5 in).
  2. Gently remove your hands. Allow the vehicle to settle.
  3. Repeat the previous two steps two more times, for a total of three times.

  4. Object Number: 217628  Size: SH
  5. Measure from the bottom of the rear axle stop bracket (1) to the top of the rear axle (2) to obtain the D height dimension.
  6. Push the rear bumper of the vehicle down about 38 mm (1.5 in).
  7. Gently remove your hands.
  8. Allow the vehicle to settle.
  9. Repeat the previous two steps two more times, for a total of three times.
  10. Measure from the bottom of the rear axle stop bracket (1) to the top of the rear axle (2) to obtain the D height dimension.
  11. Find the average of the high measurements and the low measurements in order to determine the D height dimension.