This rear straw-walker shaft transmits rotary motion from the walker drive to the rear set of walker cranks, synchronizing the oscillating motion that separates grain from the straw mat. It spans the width of the walker assembly and connects to the bearing housings at each side. A worn shaft or damaged bearing journal causes uneven walker timing, leading to incomplete separation and increased grain loss out the rear of the combine. The shaft is machined to match the original assembly's journal diameters and keyway positions, so the existing bearings and sprockets mount without modification. On installation, inspect the bearing bores for wear and replace the seals.