This V-belt transmits drive from the engine to the reel variator on a grain harvester. It sits in the pulley set that adjusts reel speed relative to ground speed, allowing the operator to match reel rotation to crop conditions. A worn or glazed belt slips under load, causing the reel to slow and leading to uneven crop feeding into the header auger. The belt is constructed by Gates to match the original cross-section and length profile, which keeps the tension within the variator’s adjustment range and prevents premature pulley wear. On replacement, ensure the belt is seated fully in both pulley grooves and that the tensioner is set to the manufacturer’s specification.