This plastic bushing acts as a bearing surface for the fan wheel shaft within the threshing drive assembly. It supports the rotating shaft and maintains alignment between the fan wheel and its housing, reducing metal-on-metal contact. Wear on the bushing bore allows shaft play, which can cause the fan wheel to rub against the housing or produce vibration in the drive line. The bushing is manufactured to the original inner and outer diameter tolerances so it seats correctly in the housing bore without modification. On installation, verify the shaft is clean and free of burrs to prevent premature bushing wear.