Wheel-Checks are loose wheel nut indicators that allow a loose wheel nut to be identified with a simple visual inspection. When the wheel nuts are properly torqued to specs, the Wheel-Checks are then placed on the wheel nuts in a uniform pattern.
Once a wheel nut has loosened, the Wheel-Checks will become out of sequence. It will be visible when the driver does a walk-around check. It is then the driver’s responsibility to call maintenance and have the wheel thoroughly serviced.
Wheel-Checks are also heat sensitive, the company said. If there is a binding brake or seized bearing, the heat is transferred through the stud and nut. If this temperature exceeds 120 degrees C (248 degrees F), the Wheel-Check will start to blister around the circumference and eventually begin to distort. The driver will be required to go to maintenance and have a thorough assessment on the problem wheel.