Call Tim's Outboard, Hackensack MN. They are the very best for clean used or new parts 218 682 2331. Tell 'em Tim sent ya. The o ring for shift shaft is harder to change, I have a trick that makes it real easy. Is there fishing line on the prop shaft? Do you tow the boat while it is in neutral? Not smart.......Why? The prop spins and damages the outer seal which is supposed to be lubed and cooled with water. For testing with pressure, what I made is an adapter that fits on my Stant radiator tester. I COMPLETELY drain all lube/water out of unit, then put in the upper plug/vent screw. Add about 15 psi with my radiator tester which has a small hand pump. Then I check with soapy water if it won't hold pressure while I wiggle and turn shafts, move shift rod, well you get the idea. You can't effectively directly see the leaking air around the imput shaft because of the water pump is in the way. So if you are loosing pressure and the other areas are not showing a leak, you have to suspect the imput shaft seal, or bearing retainer housing seal.