Mercury 35/40HP 2 Cylinder Outboards Service Manual PN 90-42794--1, Page 153Get this manual
7Apply Quicksilver 2-4-C Marine Lubricant to drive shaft splines, shift shaft splines and 1.0of water tube sealDO NOT apply lubricant to top of shift shaft or drive shaft8Install water tube (a) into drive shaft housing and insert into seal located at bottom of exhaust plate Filling Gear Housing with Lubricant
1I nstall new gaskets on fill and vent screws2With gear housing in vertical position, fill gear case thru "Fill" hole (a) using Quicksilver Gear Lube until lubricant flows thru "Vent" hole (b) and no air bubbles are visible3Drain approximately one fluid ounce (30cc) of lubricant from gear housing to allow for lubricant expansion4Install "vent" screwRemove lubricant tube and quickly install "Fill" screw