Measuring the J and K Dimension

Fig 1: Measuring J & K Dimension

Courtesy of GENERAL MOTORS CORP.

Use the following procedure to check the J and K dimensions:

1. Measuring the J dimension for the left and right side of the vehicle inboard of the pinch-weld flange at 544 mm (21.4 in) from the centerline of the front wheel.
2. Compare the measurement to the J specification. Refer to Trim Height Specifications .
3. If the measurement is outside of the specified range, replace the front springs. Refer to Strut, Strut Component and/or Spring Replacement in Front Suspension.
4. Using your hands, lift the rear bumper approximately 38 mm (1.59 in).
5. Gently remove your hands and allow the vehicle to lower.
6. Using your hands, jounce the rear of the vehicle downward approximately 38 mm (1.59 in).
7. Gently remove your hands and allow the vehicle to rise.
8. Measuring the K dimension for the left and right side of the vehicle inboard of the pinch-weld flange at 560 mm (22 in) from the centerline of the rear wheel.
9. Compare the measurement to the K specification. Refer to Trim Height Specifications .
10. If the measurement is outside of the specified range, replace the rear springs. Refer to Coil Spring Replacement in Rear Suspension.