Vehicle Lean - Left Front Sits Low or Right Rear High (Add Spacer Between Left Rear Spring Pack and Axle)

This bulletin is being revised to update the models to reflect that bulletin only applies to 1500 (½ Ton) Series. Please discard Corporate Bulletin Number 06-03-06-005 (Section 03 -- Suspension).

Some customers may comment that their vehicle appears to lean. In most cases, the vehicle will sit low left front or high right rear.

Measure fender wheel-opening heights, front and rear, to quantify vehicle lean. Fender wheel-opening heights are related to, but distinct from, trim height (a.k.a. Z and D height). The front wheel-opening height is known as P height, and the rear wheel-opening height is know as R height. The P and R heights are not set at the factory, nor is a specification given for them. However, they are the most direct and repeatable measurement of what a customer would see as the vehicle leaning. Perform the following before measuring the fender wheel-opening heights:

P Height and R Height Measurements

P height and R height are measured the same way. They are the distance from the ground to the highest point on their respective wheel-opening, going through the center of their respective wheel. Record the measurement on the repair order.

If the difference from left to right for P and R height is 15 mm (0.59 in) or less, no repairs are suggested as the vehicle is within specification. If the difference exceeds 15 mm (0.59 in) for either measurement, install the spring spacer to the left rear side of the vehicle following the procedure below.

1. Raise and support the vehicle.
2. Support the rear axle.
3. Remove the U-bolt nuts, remove the U-bolts and anchor plate. Discard the U-bolts. DO NOT discard the nuts or anchor plate.
4. Remove the lower shock nut and bolt.
5. Raise the vehicle or lower the axle enough to allow for installation of the spacer. Install the spacer, P/N 15872657.
6. Lower the vehicle or raise the axle.
7. Install the lower shock nut and bolt.

Tighten
Tighten to 95 N·m (70 lb ft).

8. Install the anchor plate, new longer U-bolts, P/N 15872655, and nuts.

Tighten
Tighten the nuts to 72 N·m (53 lb ft).

9. Remove the axle support and lower the vehicle.
10. Re-check the P and R heights in the previous location. Record these readings on the repair order.
11. After all measurements are done, perform a road test and check headlight aim.

If these steps do not resolve the condition, please contact GM TAC for further diagnostic assistance.

For vehicles repaired under warranty, use: