Modern Chevrolet trucks use torsion bar suspensions for four-wheel-drive models. These front springs have the advantage of size and can be adjusted with small bolts where the bar meets the frame. The average backyard mechanic can adjust the torsion bars of a Chevrolet pickup in about 20 minutes.
1. Lift the truck by placing the floor jack on the frame rail directly behind a front wheel and pumping the jack’s lever until the wheel is in the air.
2. Place a jack stand onto the frame rail, close to the floor jack. This is to support the vehicle if the floor jack should fail.
3. Locate the torsion bar adjustment bolt, underneath the frame rail directly behind the torsion bar. It is embedded into the torsion bar mount, which has the appearance of a two-plated bracket. Viewing the mount from the underside, it is nestled into the mount and accessible vertically.
4. Mark the torsion bar adjustment bolt with a grease pen by placing a line on the head of the bolt, and a similar line on the mount brace. This is to give a reference for the bolt’s original position.
5. Turn the bolt with a socket (18mm for most trucks) clockwise to raise the pressure on the torsion bar. Each full turn will raise the truck about a quarter inch when it is lowered from the jack and stand. Turning the bolt counterclockwise will lower the truck.
6. Lower the truck by removing the jack stand and turning the pressure screw on the jack in a counterclockwise direction slowly.
7. Repeat the process on the opposite side torsion bar adjustment bolt, as they must be turned equally to maintain stability and be level.