Bearing fluting is a type of motor bearing damage that causes the motor to stop working properly. Fluting damage appears as washboard-like ridges that develop on the bearing raceway. The first indication of a problem is usually loud noise that develops when the bearing balls travel over frosted and pitted surfaces. By the time noise develops, however, the motor has typically sustained extensive amounts of damage. Using insulated bearings, shielded cables, and grounding the motor shaft can prevent damaging fluting. Properly maintaining the motor and regularly inspecting the bearings for signs of damage also prevent bearing fluting.