This gear transfers drive from the chain-conveyor sprocket to the auger or elevator that moves harvested grain through the unloading system. It is mounted on the shaft inside the conveyor housing and meshes with a matching sprocket on the driven side of the loop. A worn or broken tooth causes intermittent drive, leading to plugging or uneven grain flow at the discharge point. The manufacturer machines the bore and tooth profile to match the original shaft fit, so no bushing or shimming is required during replacement. On reinstall, verify that the retaining pin or key is seated fully and that the gear rotates freely before closing the housing.