The Eaton Fuller Mainshaft, part number 23126, is a genuine Eaton Fuller manual transmission component used in heavy-duty drivetrain applications. The mainshaft is a core internal shaft within the transmission assembly, transferring torque through the gear train. Pro Gear and Transmission carries genuine Eaton Fuller parts. Not sure this is your part? Give us a call to confirm proper fit for your specific transmission and application before ordering.Interchanges:HF23126FeaturesGenuine Eaton Fuller manual transmission mainshaftPart number 23126Internal torque-transferring shaft for heavy-duty manual transmissionsSold individually as a single unitAvailable from Pro Gear and Transmission