127438 Eaton Axle Shaft is a rear drive axle shaft, a genuine Eaton part from Pro Gear and Transmission. Our parts manuals list it in the axle shafts assembly of the Dana Spicer 40 Series Single Reduction Tandem Drive Axle, DS404 / RS404, DS405, DSH40, DSH44, DSP41 Single Reduction, DST40 and DST41 axles.The splines are what lock the shaft to the differential gearing, so drive torque passes out to the wheel end without slipping. Vibration, unusual noise, uneven power delivery, or visible wear on the shaft are reasons to pull it and inspect it. A failing shaft left in service can speed up wear on the driveline parts around it. Call us to confirm proper fit for your application.Interchanges:920191Mack 2719-127438FeaturesRear drive axle shaft, part number 127438Listed in the axle shafts assembly of the Dana Spicer DSH40, DSH44, DS404 / RS404, DS405, DSP41, DST40 and DST41 axles, and the 40 Series Single Reduction Tandem Drive AxleSplined to the differential gearing to carry drive torque out to the wheel endVibration, noise or visible wear on the shaft are the cues to inspect itA genuine Eaton part from Pro Gear and TransmissionUsed in these Dana Spicer models40 Series Single Reduction Tandem Drive AxleDS404 / RS404 Tandem Drive AxleDS405 Tandem Drive AxleDSH40 Tandem Drive AxleDSH44 Tandem Drive AxleDSP41 Single Reduction Drive AxleDST40 Tandem Drive AxleDST41 Tandem Drive Axle