1960's 18HP evinrude issue

[Fishin4Life]

I have an old evinrude that leaks lower unit fluid. I purchased a lower unit gear gasket set, installed some new gaskets hoping to correct the problem, only to make it worse. It appears to be leaking right in the area where the shaft comes out to the prop, does anyone have any suggestions on what I should do? It is starting to drive me crazy.

[Surface Tension]

Did you replace the prop shaft seal and if so did it get pressed in evenly without distorting the seal?

[Fishin4Life]

I used a press to put it in with a socket as a guide. I am pretty sure it went in smooth. The old one was a pain to remove.

[Surface Tension]

Take the prop off to see where exactly the lube is coming from. I believe theres a large O-ring and the gasket you should have replaced as well. Is it possible you didn't prep that surface completely, leaving some old gasket behind?

If its coming from the shaft seal you replaced.

Possible wrong size seal, bent prop shaft, worn prop shaft, worn bearing or bushing causing enough slop to allow prop shaft to wobble.

[musky hunter]

The shaft seals work just like any other bearing fit seal. Becasue you already replaced them once, either it was damaged in the installation or the shaft is worn. The condition is called fretting, a chemical reaction that occurs where the seal rubs on the shaft and actually can cut a groove in the shaft right where the shaft seal goes. It it a slow process but after years of rotating it finally wears enough that the seal is no longer effective. Unfortunatly, if this is the problem, it's either replace the shaft, have it repaired by a really good machine shop and hope the welding doesn't soften and warp the shaft too much, or suffer with the problem. You might be able to get by with shimming the seal so it does not protrude in quite so far and then seals on the unworn portion of the shaft, but that I am uncertain that there is enough clearance to work. My vote would be to find a good used shaft for the unit and a new seal.

[Fishin4Life]

Surface - I replaced both o-rings. It is possible that one may have gotten pinched on installation, but I don't think so.

As with the prop shaft. That could be the issue I didn't see any groves in particular, but I have a spare lower end (that I already had to use the skeg out of) that I could swap out the prop shaft. I am just getting so fed up with this lower end I might just drop it off at a marine shop and say fix it, if it is under $200. If not screw it, and when it breaks a new motor is in store for me! Thanks for all your help as I will try both of those suggestions. Anyone want to sell a 15hp for cheap?! LOL

[Fishin4Life]

Quick question about this whole deal. It appears to be an o-ring problem, does anyone see a problem with sealing the skag with some kind of silicone gasket material instead of the o-rings? I think this would make a much better seal, and form into all the weird groves and such. I am also going to press in a new prop shaft seal. Is there any reason I shouldn't do this? My motorcycle case is sealed in the middle with that stuff and it has held strong for going on 26 years now! LOL

[Surface Tension]

I won't tell if you don't.

[Fishin4Life]

Well I sealed her up today with permatex, so we will see if that holds! haha. Quick fix, but hopefully it does the trick. Everyone cross there fingers because I am going to let it sit over night and fill er up with oil tomorrow! I'll let ya know how it goes. I am going to be one angry man if this doesn't seal it up! I have had that thing ripped apart one too many times.

Oh and it started leaking because an O-ring got pinched when I put it all back together last time.

Also my prop shaft was grooved, thanks for noting that on the post. I replaced it with a spare that I had.

[Surface Tension]

Nothing worse then tearing into something over and over to correct something you did...but thats how you learn. I bet you can do the job in your sleep now.

For your sake I hope you got it.

[Fishin4Life]

So much for the cheap fix. I don't think this thing will ever stop leaking. The sealer didn't work so I threw a o-ring back in and am just going to forget about it for now. It has me so irritated.