2007 Meritor/Rockwell RT40-145, Truck Tractor, Front Rears (Tandem Front), Fits to: Mack CXN613, (Used) 2007 Mack CXN613, FRONT DIFFERENTIAL GEARS- Make: Meritor, Model: RT40-145, Ratio: 3.37, Capacity: 20,000 Lbs, Part Number: C3121R2280, Serial Number: AVH06012357, 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 3.37, Serial# AVH06012357, Truck Year 2007 1M1AK06Y17N015003