• Provides constant tension to the belt to eliminate slip or noise

• Dampens belt vibrations caused by engine firing

• Tunes the accessory drive system for proper function

• Maintains alignment of the belt

• Automatically adjusts for belt stretch and wear

Like accessory belts, automatic tensioners need to be inspected at appropriate regular vehicle maintenance intervals, and replaced when necessary. The in-vehicle packaging of automatic tensioners within the vast majority of accessory belt system layouts typically requires that ‘offset’ tension loads are transmitted through the tensioner mechanism. This is primarily due to the location of the tensioner mounting point relative to the center line of the accessory belt.

Automatic tensioners using conventional, high quality round wire torsion spring construction are inherently better able to ‘balance’ this offset load internally within the tensioner than are alternate flat wire (‘clockspring’) tensioners. This can result in generally improved tensioner alignment & durability of torsion spring tensioners in these applications. These robust torsion spring tensioner designs also do not need anti-friction PTFE filler strips as most often must be used on flatwire tensioners.