This variable speed belt transmits power from the engine to the threshing drum, allowing the drum speed to be adjusted for different crop conditions. It operates within the variator assembly, where a movable pulley sheave changes the effective diameter of the belt path. A worn or glazed belt will slip under load, causing inconsistent threshing drum speed and reduced separation efficiency. The belt is constructed by Gates to match the original profile and cord tension, which keeps the variator sheaves from developing uneven wear patterns. On installation, ensure the belt is seated fully in the pulley grooves and that the tensioner is adjusted to the manufacturer's specification.