Wheel balance weights can fall off and cause vibrations. When this happens you need to get the wheel rebalanced. It's estimated that 70,000 tons of lead weights are lost each year worldwide. Many states are banning the use of lead wheel balance weights for environmental reasons. Alternate materials such as zinc are now being used. At Greenhaven Shell in Sacramento we install quality NAPA replacement parts. Give us a call at 916.422.6053 and let us help keep you safely and economically on the road.