Belt Tensioner 21422767

This is a Belt Tensioner Assembly designed for heavy-duty engines and equipment. It plays a critical role in the engine's accessory drive system by ensuring the serpentine belt maintains constant, optimal tension.

Product Specifications

Average Weight: ~ 2 kg

Compatibility: A25D ; A30D ; A25E ; A40F/G ; A40F/G FS ; EC750D ; EC950E ; EC750E ; A45G ; A45G FS ; A60H ; L350H ; EC750E HR ; EC950F ; L350H ; A45J ; A50J ; A60J ; FH12, FH16, FM9, FM12, and NH12 series

Supersession: 8149855 > 20966526 > 20935523 > 20762060 > 21422767

SL: 3B

Key Information

This tensioner uses an internal spring-loaded mechanism to keep the serpentine belt at the precise tension required to drive the alternator, water pump, and A/C compressor. By providing consistent pressure, it compensates for the natural stretching of the belt over time and absorbs the shocks/vibrations caused by the engine's combustion cycles.

In heavy-duty Volvo engines, a failing tensioner is a "critical path" failure. If the tensioner loses its spring strength, the belt can slip, causing overheating and inconsistent voltage leading to electrical faults.