View 0 Photos View 0 Videos 2018 Eaton R40-155 Rear Differential for a Peterbilt 579 Newly Listed $1,375 USD (USED) Eaton R40-155 Ratio: 2.79 Side Gear Splines: 41 W/ Locker: YES Cast#: - ConditionUsedFits To Make(s)PeterbiltFits To Model(s)579Stock Number25990448 MLS Number14360816CategoryDifferentials, Rear Last Updated5/10/2026 LocationWinimac, IN, US Sold ByVander Haag's Inc. (855) 370-___ SHOWNUMBERCall Seller Email Seller Save More Info