Home › Forum › Ask A Member › Lower Unit Gear Lube Rule of Thumb? › Re: Lower Unit Gear Lube Rule of Thumb?
Buc,
The front cover you speak of will leak. It’s weak point is the three screw threaded holes pull out a few thousands. Use a straight edge along the mating surface to see how flat it really is. Use little plumbing washers under the three screws as well. Another leaking point is the aluminum shift tube inside the case. Remove the tube & replace the O-ring inside the pipe & replace. I had a member machine the gearcase so I could install two drive shaft seals, one up & other down to stop the driveshaft from leaking. You will find the drive shaft has pits in it. I have used JB weld to fill it in a little. Not perfect but better. I need a torch to fill it in pits with brass. The propshaft needs a seal too but replace all it’s bearings too. There is a needle right above the pinion gear too. I fill my motors with 105. It is thin enough to lube the needle bearings. Fill from the bottom up.I use a short piece of blood pressure tubing on the shift shaft rod & on to the aluminum tube to seal that guy double too.
Jeff