The movable cleaning shoe frame is provided with internal sidewalls. The frame supports a sieve for receiving grain to be cleaned. The sieve is provided with longitudinally extending dividers that define a plurality of longitudinally extending grain flow channels. The sidewalls and the dividers are provided with cleaning shoe spreaders that extend into the longitudinally extending grain flow channels above the sieve. Movement of the cleaning shoe drives the spreaders to flap back and forth. This flapping action of the spreaders distributes the grain to be cleaned transversely across the sieve so that the cleaning assembly operates more efficiently.