View 0 Photos View 0 Videos 2019 Axle Alliance RT40.0-4 Rear Differential for a Freightliner Cascadia $908 USD (USED) Alliance Axle RS21.0-4 Ratio: 2.85 Side Gear Splines: 41 W/ Locker: NO Cast#: R6813510805 ConditionUsedFits To Make(s)FreightlinerFits To Model(s)CASCADIAStock Number25901786 MLS Number13998504CategoryDifferentials, Rear Last Updated12/4/2025 LocationSpencer, IA, US Sold ByVander Haag's Inc. (855) 370-___ SHOWNUMBERCall Seller Email Seller Save More Info