View 3 Photos View 0 Videos Hydrapower M Steering Gear / Rack for a 1978 Mack RD685S Recently Updated Contact for price (Used) 1978 Mack RD685S, STEERING BOX- Make: Hydrapower, Model: M, Material: Steel, Location: Inside Frame, For more information about this item, give us a call. We ship Worldwide! (CRG... ConditionUsedFits To Make(s)MackFits To Model(s)RD685SWill Fit Year(s)1978Part NumberAF64298Stock NumberP-84850 MLS Number13012588CategorySteering Gears / Racks Last Updated3/12/2026 LocationElkton, MD, US Sold ByCRG Heavy Truck Parts (844) 402-___ SHOWNUMBERCall Seller Email Seller Save More Info