View 4 Photos View 0 Videos Dana S21-170D Rear Differential for a 2016 Peterbilt 337 Newly Listed Contact for price (Used) 2016 Peterbilt 337, DIFFERENTIAL GEARS ONLY- Part Number: 515671, Serial Number: HN04841733, Make: Spicer, Model: S21-170D, Ratio: 5.57, Capacity: 21,000 Lbs, Reference images for... ConditionUsedRear End5.57 ratioFits To Make(s)PeterbiltFits To Model(s)337Will Fit Year(s)2016Part Number515671Stock NumberP-500627 MLS Number14256845CategoryDifferentials, Rear Last Updated3/20/2026 LocationElkton, MD, US Sold ByCRG Heavy Truck Parts (844) 402-___ SHOWNUMBERCall Seller Email Seller Save More Info