2013 Spicer/Dana RST41, Truck Tractor, Rear Rears (Tandem Rear or Single), Fits to: Mack CXU613, (Used) 2013 MACK CXU613, COMPLETE REAR DIFFERENTIAL GEARS ONLY- Part Number: 513238, Serial Number: HN03999302, Make: Spicer, Model: RSt41, Ratio: 3.55, Capacity: 8,437 Lbs, For more information about this item, give us a call. We ship Worldwide! (CRG HEAVY TRUCK PARTS) 929 W PULASKI HWY ELKTON, MD 21921, Ratio 3.55, Serial# HN03999302, Casting# HN03999302 1M1AW07YXDM023833