This V-belt transmits torque from the engine pulley to the hydrostatic drive pump on a grain harvester. It sits in the drive system, connecting the engine output to the pump input that powers the machine's forward and reverse motion. A worn or stretched belt slips under load, causing erratic ground speed and reduced tractive effort. The belt's profile matches the original pulley groove geometry to maintain proper tension and prevent sidewall wear. On installation, verify the belt is fully seated in all pulley grooves and adjust the tensioner to the specified deflection.