Abstract: An improvement to the grid racks (100) in the straw walker portion of a grain combine; wherein, the grid racks (100) are provided with a plurality of apertured steps (101)(102)(103), etc. and raised side walls (108)( 109); and, the improvement comprises a plurality of auxiliary saw toothed units (12) and (13) mounted on the apertured steps (101)(102)(103), etc. of the grid racks (100) and a saw tooth panel unit (17) mounted on the sides (108)(109) of the grid rack (100) to aggressively process stalks or straw passing through the straw walker portion of the combine.