Timbren Suspension Enhancement Systems work in conjunction with the existing suspension, to improve your ride and to protect the vehicle against the effects of overloading. Hollow Timbren rubber springs are mounted between the truck frame and the axle. They do not take the place of the existing leaf spring, but work in conjunction with it, acting as a bump stop, to improve the ride of your truck and to protect springs against overloading.Timbren Ride Control products enhance a vehicle's empty ride quality, while providing protection against overloading, road shock, bottoming out, sway and broken springs. Timbren Front axle kits prevent front end nose diving Warning: This product can expose you to chemicals which is [are] known to the State of California to cause cancer and birth defects or other reproductive harm.