Mercury Mariner Outboard 225 3 Litre Service Manual 1994, Page 260Get this manual
IMPORTANT: If seal installed above pump housi ng is not at the proper height, air will be drawn into the pump resulting in overheating of the engine Gear Lubricant Filling Instructions
12Inspect "fi and "Vent" a-rings for cuts or abrasionsReplace a-rings if necessaryClean any metal debris from magnet on "Fill" plugUsing tool provided in seal kit (26-816575A2) or water pump kit (8 17275A3), press seal down overdrive shaft (DO NOT GREASE DRIVE SHAFT) until tool seats against pump housing
IMPORTANT: Never add lubricant to gear housing without first removing "Vent" screw, or gear housing cannot be filled because of trapped airFill gear housing ONLY when housing is in vertical position3Slowly fill housing thru "Fill" hole with Quicksilver Su per Duty Lower Unit Lubricant unlillubricant flows out of "Vent" hole and no air bubbles are visibleInstall "Vent" screw into "Vent" holeIMPORTANT: DO NOT lose more than one fluid ounce (30cc) of gear lubricant while reinstallingFillscrew5Remove grease tube (or hose) from "Fill" hole and quickly install "Fill" screw into "Fi ll" hole