Chevrolet cars and trucks use torsion bars where normal coil or leaf springs will not fit. The bars have the added advantage of being adjustable. The torsion bar suspension has become popular in Chevy’s 4WD truck line, in which the switch to independent front suspension (IFS) leaves little room for a standard coil spring. The average backyard mechanic can adjust the torsion bars on a Chevrolet in about 20 minutes.
Lift the Chevy with the floor jack, placing the jack head underneath a frame rail and pumping the lever until the desired wheel is in the air. This relieves the torsion bar of the weight, and makes it easier to turn the adjustment bolt. Place a jack stand near the jack head on the same frame rail, for support.