The Z71 Series trucks are made by Chevrolet, and are four wheel drive vehicles with a torsion bar front suspension. These trucks are designed to take abuse on and off road. The torsion bar sets the ride height of the Z71, and it's adjustable as well. This allows you to tune the front suspension to your specifications by either lifting up the front end or dropping it down to meet your needs.
Park the Z71 on a level surface. Set the parking brake and chock the rear wheels. Measure from the bottom of the front bumper on the truck to the ground with the tape measure.
Lift the front of the truck with the jack. Put jack stands under the frame, and make sure they're set high enough that the front wheels are off of the ground. Lower the vehicle onto the jack stands.
Slide underneath the truck and locate the torsion bar connection leading into the lower control arm. Follow the torsion bar back to the torsion bar crossmember, and find the torsion bar adjusting bolt, which is just inside the crossmember. Loosen the torsion bar adjusting bolt with the 1/2-inch ratchet and socket to lower the truck, and tighten the torsion bar to raise the front end. Count how many times the ratchet turns on one adjusting bolt, and do the same thing on the other adjusting bolts so that the front end is lifted or lowered evenly.
Lower the truck off the jack stands using a jack. Measure the distance between the bumper and the ground with the tape measure again. Compare the two measurements to determine whether you need to continue adjusting the suspension. If you do need to continue, repeat the above steps until you are satisfied.
