A dense polyurethane spacer simply slips above the coil spring and rests on the factory rubber isolator. This retains the factory spring rate so the ride remains unchanged. With the coil back in place, the floor jack can lift the axle to compress the springs. The new shocks are installed, and the brake line bolt and sway bar links reattached. The minimal lift keeps the rest of the suspension and axle components within the factory specifications, rather than having to replace drivelines and track bars like some larger lifts require.