I7- Truck Wheel Weights - Lead The most commonly used weight on heavy-duty trucks(larger than 26,000 lbs GVWR) with steel rims. Also used on some older medium-duty trucks. Fits: Most heavy-duty & some older medium-duty truckswith steel wheels Clip-on wheel weights, also referred to as knock-on weights, install onto the inner or outer lip of the wheel rim. A hammer is needed to tap the weight which crimps and secures it in place. Wheel weights require wheel balancing equipment to determine the exact placement on the rim.