View 1 Photo View 0 Videos Eaton RSH40 Rear Differential for a 2021 Peterbilt 579 $895 USD RSH40 3.55 TAKEOUT WILL INSPECT IN OUR GEAR SHOP, 90 DAY WARRANTY, Axle Spline Count: 41, Core Charge: 250.00, Ratio: 3.55 ConditionUsedRear End3.55 ratioFits To Make(s)PeterbiltFits To Model(s)579Will Fit Year(s)2021Stock Number12025-4 MLS Number13378535CategoryDifferentials, Rear Last Updated6/13/2026 LocationUcon, ID, US Sold ByHolst Truck Parts (833) 541-___ SHOWNUMBERCall Seller Email Seller Save More Info