A rethreshing system and method for a combine having a cleaning system that includes at least one sieve or like material separating mechanism. The rethreshing system includes a tailings collection pan for collecting tailings that do not pass through the sieve and a tailings rethreshing mechanism receiving the tailings from the collection pan and rethreshing the tailings. A distribution auger is arranged across a return pan of the cleaning system and is operable to substantially evenly distribute rethreshed tailings on the return pan of the cleaning system. The distribution auger includes a tubular auger housing having an entrance for receiving material to be conveyed, a closed end opposite the entrance, and a longitudinally elongated and tapered slot formation through a sidewall of the tubular auger housing, the slot formation having a small width near the entrance to the tubular housing and a wide width near the closed end of the tubular housing.