Mercury 35/40HP 2 Cylinder Outboards Service Manual PN 90-42794--1, Page 132Get this manual
4Place block(s) of wood (a) as shownThis will prevent propeller from rotating and protect hands during propeller nut removal5Remove nut and pull components from shaft 4Remove four lock nuts (a) securing gear housing to drive shaft housing (two not shown)5Remove gear housing
Gear Housing Disassembly
1Place gear housing assembly in soft jawed vise2Remove shift shaft guide (if equipped) from shift shaft