This bearing assembly supports the drum shaft within the threshing drive, maintaining correct gear alignment under load. It is mounted in a housing that bolts to the machine frame, with the inner race rotating with the shaft and the outer race fixed in the housing. A worn bearing produces audible rumble and shaft play, which leads to gear tooth misalignment and premature wear on the driven components. The housing is machined to match the original mounting face, so no shimming is required during replacement. When installing, clean the bore and apply thread-locking compound to the mounting bolts.