Measuring the P and R Dimension

Fig 1: Measuring P And R Dimension

Courtesy of GENERAL MOTORS COMPANY

Measurement Definitions 

P Height: The vertical distance from the ground to the top of the wheel opening through the centerline of the front wheel.

R Height: The vertical distance from the ground to the top of the wheel opening through the centerline of the rear wheel.

Use the following procedures to measure the P and R dimensions:

1. Push the front bumper down a minimum of 25 mm (1 in) and release. Perform this step three times.
   NOTE:

   • Measure from the center of the wheel well opening to the ground.
   • The left and right P and R height differences should be no more than 10 mm (0.39 in).
2. Measure and record the trim height per the "Measurement Definitions" above.
3. Lift the bumper up 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 P height measurement is the average of the measurements taken in step 2 and 4. Refer to Trim Height Specifications .
6. Repeat the above steps at the rear of the vehicle for the R heights.
7. If the P and R heights are outside of the specifications, measure the Z and D heights.