Mercury 35/40HP 2 Cylinder Outboards Service Manual PN 90-42794--1, Page 151Get this manual
5Install seal and washerApply Quicksilver 2-4-C Marine Lubricant to 1.0of insert and seal IMPORTANT: When performing gear housing repair that requires removal of water pump impeller, it is recommended that the impeller be replacedIf it is necessary, however, to re-use the impeller, DO NOT install in reverse to original rotation, or premature impeller failure will occurOriginal rotation is clockwise