slight oil leak

iggyw1

Master Chief Petty Officer
Joined
Oct 24, 2011
Messages
880
Well guys. I have my motor all put back together and ran it in a large barrel and thought it was all set. I noticed now one drip of oil seepage from the lower unit on my driveway. It leaked out from the seam where the lower unit gear box is connected to the exhaust leg. Evinrude model #53933 1962 40 h.p. I have a new "O" ring between the two pieces and also some permatex sealer between the pieces, but I still got the drop of oil that came out. I'm sure of where it came from (the seam) because there is a tell tale sign of oil that dripped from there. QUESTION: I covered the outside with sealer now hoping that will seal the tiny leak. (seepage is more like it) or do I need to take the thing all apart again and maybe tightem the long long bolts that are connecting the two pieces or perhaps add additional sealer between the two pieces (gear box/exhaust leg). Thanks.
 

lindy46

Captain
Joined
Nov 27, 2008
Messages
3,886
Re: slight oil leak

O-ring? There is no O-ring between the lower unit and the leg. It just bolts up there - no sealant required. Or are you referring to where the skeg attaches to the gear housing? There is no O-ring there either, just a spaghetti seal. ????
 

iggyw1

Master Chief Petty Officer
Joined
Oct 24, 2011
Messages
880
Re: slight oil leak

Yes, you are correct. I looked in my book and did not see an O ring. I was thinking of the seal that I replaced for the drive shaft up higher when I said O ring, however, I did put some sealant on the top surface of the gear box before I married the gear box to the exhaust leg. Does this sealant need to come off now? Also, there are two long " studs" that I may be able to tighten a bit, but I'm awfully scared that I'm gong to snap one or both when I'm tightening them. Anyone know what the troque should be on those stud nuts? If there is no O ring nor no sealer required between the gear housing and the exhaust leg, what is to keep the lower gear oil from leaking out at that seam?
 

emoney

Commander
Joined
Jul 19, 2010
Messages
2,551
Re: slight oil leak

Odds are what you're seeing is unburned fuel/oil mix. It's very normal to have some minor seepage. Not sure how much "sealer" you put there, but if it's very much, I'd drop the lower leg and scrape it off. Water seeps out through that joint while you're operating and you don't want it to not be able to, I'd think.

The water pump and housing is sealed and that's what keeps you lower unit fluid from coming out, btw.
 

iggyw1

Master Chief Petty Officer
Joined
Oct 24, 2011
Messages
880
Re: slight oil leak

No it is definately lower unit gear oil that I am seeing. It is green in color, the same as the color of oil that I put into the gear case, and there should really be no water coming out of that seam either as the seam is between the gear box and exhaust leg. There is a tiny hole of sorts kinda drilled into the leg at the bottom of the exhaust leg. That's probably where any water may seep out if any. The oil seepage is below that, at the seam. I think if I tighten the long studs (which I removed when disasembling the motor) it will draw tighter a bit. I did not put a lot of sealant between the two parts. Just kind of rubbed it on very thin with my finger is all. I still would like to use a torque wrench on the nuts for the studs, but it does not mention the torque in my service manual. Can anyone help me out on that?
 
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