2001 Mercury Mariner 50-60HP Factory Service Manual, Page 513Get this manual
BIGFOOT GEAR HOUSING
4If pressure drop is noted, immerse housing in water5Re-pressurize to 10-12 psi (69-83 kPa) and check for air bubbles6Replace leaking seals as necessaryRetest housing
NOTE: Gearcase should hold 10-12 psi (69-83 kPa) for minutes7Remove tester from housing and install vent plug and sealing washer
Filling Gear Housing With Lubricant
NOTE: Gear housing lubricant capacity is 24 fl oz (710 mL)
WARNING