An on vehicle wheel balancer allows a wheel to be balanced while it remains mounted on the car. The device slides under the tire and uses a roller system so the wheel can spin freely without being removed. Sensors or visual indicators then show where imbalance exists, allowing weights to be added directly to the wheel. Balancing a wheel on the vehicle accounts for more than just the tire and rim. It also includes the brake rotor or drum, wheel hub, studs, and even small tolerances in bearings. T