Lower Unit

[Deanrt]

Hi everyone, I have a '76 Evinrude 35 hp. I had it at the shop a few months ago for some work and they said they checked the lower unit, found it to be a bit 'milky' so they changed it and told me to check it in about 5 hours running time. Well about 5 hrs. later I check it and its milky again so I decide to change it, I pull both plugs and what oil is in there just kinda drips out. Long story short I got maybe 2 or 3 oz. out of it. It calls for 9.5 oz. Where did it go? Talked to a few people and said I should have seen it on my driveway, nope none there. So do you think the shop actually changed and fillled it or pulled a fast one on me? Thanks, Dean

 

[Whoopbass]

Re: Lower Unit

Looks like your going to have to fill it back up with oil and run it again so you can be sure.
If you are actually losing that much oil you must have a major leak that is leaking into the lake.
My 1980 25 Johnson had bad seal(s) in the lower unit for years. The oil was always milky and sometimes low but I don't recall it leaking in the driveway.

I finally got around to installing a seal kit the other day. I pulled it apart and the gears still looked new. There was a small magnet inside of the lower unit and there wasn't any metal on it. Having milky oil for 10 years didn't hurt my lower unit at all.
The seal kit wasn't that hard to put on. The hardest part is removing the old seals.

 

[Deanrt]

Re: Lower Unit

Yeah thats what I did I just havent had a chance to get on the water yet. Still seems a little fishie.

 

[OptsyEagle]

Re: Lower Unit

It would obviously depend on the leak, but I would suspect that most of the leaking would come when the motor is in use. That oil is pretty thick stuff, so it most likely leaks out when in use as the heat build up increases the pressure on those seals by a few psi, and upon cool down when the resulting reduction in pressure puts a vacuum on those seals.

So, I would suspect that as you are ripping down the lake, the oil is seeping out and as you cool her down the water is seeping in and so on. Others can confirm or refute my thoughts, but I doubt much happens at all when it is sitting in your driveway.

 

[Deanrt]

Re: Lower Unit

Thanks OE, that's the only thing that makes any sense at this point. Sounds like a L/U rebuild is in my near future. Kinda scary since the last time I had the boat out we were about 6 miles out in the ocean. I never leave home without a backup or kicker motor but still!

 

[samo_ott]

Re: Lower Unit

That's what a kicker or Sea Tow is for!

 

[tomynoks]

Re: Lower Unit

Whoopass.... or anyone.... you said, "The seal kit wasn't that hard to put on. The hardest part is removing the old seals."

That's what I'm looking for... how to remove the old seals! How did you do it?

I'm putting a seal kit on my '69 Johnson 115 and that's what I'm stuck on. I have a seal that goes over the water pump housing and don't want to damage anything prying that old seal out.

Thanks,

Tom Smith