22674901
Belt Tensioner
Mack

The belt tensioner maintains constant tension on the serpentine or drive belt, ensuring consistent operation of the alternator, power steering pump, water pump, and air conditioning compressor. A modern auto-tensioner uses an integrated spring and pulley to adapt to engine movement and belt wear, preventing belt slip and reducing noise. Proper tensioning improves reliability and longevity of the belt set, reducing heat generation and mechanical wear. A failing tensioner often manifests as squealing belts, uneven idler operation, or erratic accessory performance; replacement intervals are guided by service schedules and belt condition. The tensioner also contributes to fuel efficiency by minimizing belt drag and maintaining optimum pulley alignment. When replacing, check pulley cleanliness, bearing condition, and the torque of mounting bolts to spec. A high-quality tensioner with a durable bearing and robust spring helps protect critical accessories in demanding conditions. For trusted parts, Source One Parts Center has you covered.