GM Service Manual Online
For 1990-2009 cars only

The four angles of concern in the front end are toe-in, the caster angle, the camber angle and the king pin inclination.

These points should be checked with precision instruments at regular intervals. Refer to the Maintenance Schedule. This is particularly important when the front axle has been subject to heavy impacts due to a collision or hard bumps.

It is important that the tires be inflated to the proper pressure and that the wheel bearings be in proper adjustment when checking the wheel alignment. Uneven tire pressure and loose bearings will affect the readings on the wheel alignment instruments.

The P72 and the P92 chassis use heavy-duty, I-beam front axles, so only toe-in is adjustable. The other three angles are built into the design of the front axle. If the caster, the camber or the king pin inclination angles are incorrect, the axle must be replaced.

Important: Do not attempt to align the axle by bending it.