Abstract: A grain combine is disclosed having an improved straw walker for separating grain from chaff and for transporting the straw toward one end of the combine. The improved straw walker comprises a housing within which are mounted a plurality of parallel generally horizontally disposed straw walker boards or channels, each having parallel side walls with upwardly directed teeth along their upper edges. The channels are mounted for orbital motion upon two or more parallel crankshafts by the provision of split bearings connected to each straw walker. Each split bearing includes bearing halves that enclose a bushing through which the crankshaft extends. The crankshafts themselves are each mounted for rotation upon journals supported upon the framework of the combine. Each crankshaft is built up from separate pieces comprising crank arms bored to receive crank throw pins and shaft pins, all rigidly connected together by retaining pins or other suitable fasteners.