ISB6.7 Cummins Belt Tensioner 3976831 Parts Catalog Ref No. Part Name Part No. Required 1 Belt Tensioner 3976831 1 2 Hexagon Flange Head Cap Screw 3900679 1 Above is the introduction of the 3976831 Cummins Belt Tensioner, while if you need Belt Tensioner 3976831, complete Cummins engine or other Cummins product, please further consult our sales.