This bearing shell is the replaceable wear surface for the walker assembly in the threshing unit. It sits between the walker shaft and its housing, reducing friction as the shaft oscillates to convey material through the separator. Wear on the shell increases clearance, which leads to knocking and accelerated damage to the shaft journal. The shell is machined to match the original housing bore diameter so that no shimming is required during installation. Replace the shell when disassembling the walker for any other service.