Dayco tensioner pulleys are used to provide proper tension on the engine belts and keep the car and truck belts tight. They are also responsible for maintaining proper alignment of the engine drive belt and are available in both light- and heavy-duty variants. These pulleys have lubricated bearings, smooth surface and firm dimensional tolerance and, therefore, have less vibration and increased service life. Dayco belt tensioner pulleys are available in high-strength and wear-resistant steel, powdered metal and plastic materials for use in various harsh environments.