Z Height Measurement

WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2004 GMC Sierra, 2004 GMC Cab & Chassis Sierra, 2004 Chevrolet Silverado, 2004 Chevrolet Cab & Chassis Silverado, and 2003 GMC Sierra. However, it is still accessible from the selected car via links, so may be relevant.

IMPORTANT: K models only the Z height must be adjusted before the alignment.

The Z height dimension measurement determines the proper ride height for the front end of the vehicle. Vehicles equipped with torsion bars use a adjusting arm in order to adjust the Z height dimension. Vehicles without torsion bars have no adjustment and could require replacement of suspension components.

IMPORTANT: All dimensions are measured vertical to the ground. Cross vehicle Z heights should be within 12 mm (0.47 in) to be considered correct.

Place hand on the front bumper and jounce the front of the vehicle. Make sure that there is at least 38 mm (1.5 in) of movement while jouncing.
Allow the vehicle to settle into position.

Fig 1: Measuring Front Z Height

Courtesy of GENERAL MOTORS CORP.

Measure from the pivot bolt center line (2) down to the lower corner (5) of the steering knuckle (1) in order to obtain the Z height measurement (4).
Repeat the jouncing operation 2 more times for a total of 3 times.
Use the highest and the lowest measurements to calculate the average height.
The true Z height dimension number is the average of the highest and the lowest measurements. Refer to Trim Height Specifications .