2001 Mercury Mariner 50-60HP Factory Service Manual, Page 514Get this manual
BIGFOOT GEAR HOUSING 53922
a -Vent ScrewTorque to 60 lb-in(6.8 Nm) -FillDrain ScrewTorque to 60 lb-in(6.8 Nm) -Oil Level Vent ScrewTorque to 60 lb-in(6.8 Nm) 8Replace second lubricant "Vent" screw and sealing washerIMPORTANT: Do not lose more than one fluid ounce (30cc) of gear lubricant while reinstalling "FILLDRAIN" screw9Remove lubricant tube from FillDrain hole; install FillDrain screw and sealing washer