The Dana Spicer 3900904 is a thrust washer designed for driveline and drive shaft applications. This part carries OEM part number 3900904 and is also referenced as SI3900904 in aftermarket catalogs. Thrust washers in driveline assemblies control axial load and reduce wear between rotating components at the drive shaft. The 3900904 is sold individually (unit of measure: each) by Pro Gear and Transmission. If you need help confirming this is the correct thrust washer for your application, give us a call.FeaturesDana Spicer OEM part number 3900904Also cataloged as SI3900904 in aftermarket referencesDesigned for driveline and drive shaft applicationsSold individually (each)Genuine Dana Spicer driveline component