This V-belt transmits drive torque from the engine pulley to the chopper drum input shaft. It sits in the drive system of the forage harvester, connecting the primary power source to the rotating assembly that processes crop material. A worn or stretched belt slips under load, causing a drop in chopper drum speed and uneven cut quality. The manufacturer machines this belt to match the original cross-section profile, which keeps the belt seated correctly in the pulley grooves without requiring tensioner adjustment beyond the standard range.