2001 Mercury Mariner 50-60HP Factory Service Manual, Page 455Get this manual
NON-BIGFOOT GEAR HOUSING
Filling Gear Housing with Lubricant
NOTE: Gear housing lubricant capacity is approximately 11.5 floz(340 ml)
WARNING
If gear housing is installed on outboard, disconnect (and isolate) spark plug leads from spark plugs before working near the propeller
CAUTION
Do not use automotive grease in the gear housingUse only Quicksilver Gear Lube1Remove any gasket material from "FillDrain" and "Vent" plugs and gear housingInstall new sealing washers on "FillDrain" and "Vent" plugsIMPORTANT: Never add lubricant without removing "Vent" plugsGear housing cannot be filled because of trapped airFill gear housing when driveshaft is in vertical position2Remove "FillDrain" plug and sealing washer3Insert lubricant tube in "FillDrain" hole, then remove "Vent" plugs and sealing washer4Fill until excess lubricant flows out of left "Vent" hole5Replace left "Vent" plug and sealing washer and continue to fill until lubricant flows from right "Vent" hole6Replace right "Vent" plug and sealing washer7Install "FillDrain" plug and sealing washer8Torque screws to specified torque