1988-1992 Mercury Force 5HP Outboards Service Manual, Page 218Get this manual
FTESTING GEAR HOUSING PRESSURE 1Remove plug from lower starboard side of gear housingThread adapter of pressure tester (Special Tool No 8950) into drain and tighten securelyMake sure that vent screw (A) is securely tightened: 30 inIbs(3.4 Nm)3
IMPORTANT
Seals may be damaged if pressure exceeds 10 PSIPressurize housing to 10 PSI and observe gauge for five minutesIf pressure drops, immerse housing in water and repressurize (10 PSI)Replace seals wherever air bubbles appear, then retestRemove tester and "vent" screw with washer (A)Fill gear housing with gear lube through lower plug screw hole until it appears at "vent" hole (A)Install lower gear housing screw with washer Torque to 50 in.lbs(5.7 Nm)68