Mercury Mariner Outboard 225 3 Litre Service Manual 1994, Page 18Get this manual
1Tilt outboard so that lubricant in gear housing will drain toward front of housingout fi ll hole and into clean containerIMPORTANT: Inspect FILL and VENT plug O-rings for damageUse new a-rings as needed 234Remove lubricant fill plug and O-ring Note amount of metal particles on magnetic fill plugRemove VENT plug with O-ring and allow sufficient time for all lubricant to drainInspect gear lubricant for metal particles (lubricant will have metal flake appearance) Presence of fine metal particles (resembling powder) on the drain plug bar magnet indicates the need for gear housing disassembly and component inspectionNote color of gear lubricantWhite or cream color indicates presence of water in lubricantGear lubricant which has been drained from gear case recently in operation will have yellowish color due to lubricant agitationaerationThis is normal and should not be confused with the presence of waterPresence of water in gear lubricant indicates the need for disassembly and inspection of oil sealsseal surfaces, a-rings, water pump gaskets as well as gear housing components for damage8 Trim Rod Ball Ends IMPORTANT: Never add lubricant to gear housing without first removing VENT plug, as trapped air will prevent housing from being filled Fill gear housing only when outboard is in operating position 7With outboard in operating positioninsert lubricant tube into fill hole