This V-belt transmits drive from the engine or gearbox to the sieve assembly in a grain harvester. It sits on the pulley system that oscillates the cleaning shoe, maintaining the correct speed ratio between the upper and lower sieve decks. A worn or slipping belt reduces sieve stroke amplitude, which allows chaff carryover into the grain tank. The belt is constructed with a notched profile to flex around small-diameter pulleys without generating excessive heat. On installation, verify the tensioner is within its working range and that the belt tracks centered on each pulley flange.