The PAI 880878 Belt Tensioner maintains proper serpentine belt tension in heavy‑duty Mack and Volvo engine accessory drive systems. It is designed for Mack MP7, Mack MP8, Volvo D11, and Volvo D13 engines and installs in the Front Engine Accessory Drive System, with Manufacturer Part Number 880878, to support reliable operation of engine‑driven accessories. This unit replaces OEM part number 21454379 and is commonly used during belt drive repairs, preventive maintenance, and tensioner replacement to reduce belt wear and extend accessory life.
