This gear drives the chain conveyor that moves harvested grain from the feeder housing toward the threshing drum. It is positioned at the drive end of the conveyor shaft and meshes with the mating sprocket on the idler assembly. A worn or broken tooth causes the conveyor to slip, resulting in uneven material flow and potential blockages at the drum inlet. As an original part, the tooth profile and bore diameter match the factory shaft and chain pitch, so no shimming or bushing is needed during replacement. On installation, verify that the retaining clip or bolt is torqued to specification.