GM Service Manual Online
For 1990-2009 cars only

The front suspension allows each wheel to compensate for changes in the road surface without affecting the opposite wheel. Each wheel independently connects to the frame with a steering knuckle, ball joint assemblies, and upper and lower control arms.

The control arms specifically allow the steering knuckles to move in a three-dimensional arc. Two tie rods connect to steering arms on the knuckles and an intermediate rod. These operate the front wheels.

The two-wheel drive vehicles have coil chassis springs. These springs are mounted between the spring housings on the frame and the lower control arms. Double, direct acting shock absorbers are inside the coil springs. The coil springs attach to the lower control arms and offer ride control.

The upper part of each shock absorber extends through the upper control arm frame bracket. This bracket has two grommets, two grommet retainers, and a nut.

A spring stabilizer shaft controls the side roll of the front suspension. This shaft is mounted in rubber bushings that are held by brackets to the frame side rails. The ends of the stabilizer shaft connect to the lower control arms with link bolts. Rubber grommets isolate these link bolts. Rubber bushings attach the upper control arm to a cross shaft. Frame brackets bolt the cross shaft.

A ball joint assembly is riveted to the outer end of the upper control arm. A rubber spring in the control arm assures that the ball seats properly in the socket. A castellated nut and a cotter pin join the steering knuckle to the upper ball joint.

The inner ends of the lower control arm have pressed-in bushings. The bolts pass through the bushings and join the arm to the frame. The lower ball joint assembly is a press fit in the lower control arm and attaches to the steering knuckle with a castellated nut and a cotter pin.

Ball socket assemblies have rubber grease seals. These seals prevent entry of moisture and dirt and damage to the bearing surfaces.

Four-wheel drive models have a front suspension that consists of the control arms, a stabilizer bar, a shock absorber, and right and left torsion bars. The torsion bars replace the conventional coil springs. The lower control arm attaches to the front end of the torsion bar. The rear end of the torsion bar mounts on an adjustable arm at the crossmember. This arm adjustment controls the vehicle trim height.

Two-wheel drive vehicles have tapered roller sheel bearings. These bearings are adjustible and need lubrication.

Four-wheel drive models and RWD Utilities have sealed front-wheel bearings. These bearings are pre-adjusted and need no lubrication.

Heat treatment may create darkened areas on the bearing assembly. This discoloration does not signal a need for replacement.