25195022
Belt Tensioner
Mack

The Belt Tensioner is a maintenance-critical component that automatically applies proper tension to the serpentine belt system. By maintaining consistent tension, it prevents belt slip, reduces belt wear, and ensures the alternator, water pump, and other driven accessories operate reliably. The tensioner housing integrates a calibrated spring, pulley, and bearing assembly designed to withstand engine heat, dirt, and constant cycling. Regular checks for wear, misalignment, and bearing sound can prevent unexpected belt failures that might impact charging, cooling, or hydraulic systems. A well-maintained tensioner contributes to better fuel economy, smoother engine operation, and fewer roadside failures. Replacement is straightforward when signs of noise, cracking in the pulley, or excessive belt wear appear. Available through Source One Parts Center.