Automatic Belt Tensioners

Dayco® No Slack™ Automatic Belt Tensioner

Designed to maintain constant tension on serpentine belt drives
Serpentine belt drives consist of a single belt that powers most, if not all, of the engine’s accessories.To maintain the proper tension throughout the drive, an automatic, spring-loaded tensioner is incorporated into the drive system geometry. Dayco’s Automatic Belt Tensioner features a patented “flat spring” design that’s engineered to provide less operating range variations in tension. This reduces the risk of premature accessory bearing failure due to high tension when a new belt is installed. It also lessens the risk of belt squeal and slippage, or poor accessory performance caused by low tension after the belt begins to stretch and wear. A Teflon® strip wound within the spring resists abrasion. The flat spring itself is coated to resist rust.

Other superior design features include a steel locator pin (where the application demands). A heavy-duty cast aluminum spring case resists cracking and fatigue. The heavy-duty cast aluminum arm offers additional strength and less distortion . An aluminum retainer ring locks the spring case and arm together, and seals against corrosion.A steel pivot tube (where the application demands) provides additional strength for critical torque requirements. A thermoplastic rubber “spring slot plug” keeps out harmful contaminants. The lubricated nylon “pivot tube bushing” and “spring bushing” promote quieter performance.A rubber “O” ring seals against dust and grime.The zinc coated mounting bolt resists rust, and is concentric for a more even degree of constant tension. In order to meet OEM performance standards, Dayco Automatic Tensioners come with either a glass-filled polymer (plastic) or steel pulley, that features a dust cover to protect against contaminants.