The Chevrolet Silverado truck is manufactured with a front torsion bar suspension system on four-wheel-drive models. The system is used to provide room for the transfer case, which is not required for two-wheel-drive coil spring models. The average backyard mechanic can lift the front end of a Sliverado by adjusting the torsion bolts in about 30 minutes.
1. Raise the truck at the front wheel by placing the floor jack on a frame rail and pumping the lever until the wheel is off the ground. This relieves the weight on the suspension, making it easier to adjust the spring. Place a jack stand on the frame rail to support the floor jack.
2. Locate the torsion bar mount, just behind the front wheel on the frame rail. It has the appearance of two plates holding a long rod to the frame rail. Locate the torsion bar adjustment bolt, nestled up into the mount. It is a vertical bolt that sets the pressure for the torsion bar. It can only be seen when looking from underneath. Mark the head with a grease pen, so the original position is known.
3. Turn the torsion adjustment bolt clockwise with a 18mm socket wrench to raise the truck. Every half-turn of the bolt will result in about an 1/8 of an inch of lift on the body of the truck. Lower the truck by turning the bolt counter-clockwise. Don’t crank the adjustment bolt until it stops; this puts the torsion bars at their maximum pressure, and can wear them out quickly. Usually about two full turns from the stock position does the trick, giving about an inch of lift.
4. Lower the truck from the floor jack and stand, and measure the ride height. Repeat the process on the opposite torsion bar adjustment bolt, as they must be equal and level.