Yanmar YSM8 Water in Transmission Problem

[hopefulsailor]

I have a a boat with a YSM8 Diesel. I am having trouble keeping water out of the transmission. This is the second time I caught it in there. I usually clean it out with diesel fuel and oil, but I have no idea how it's getting in there in the first place. Thoughts? Suggestions? Ideas? Thanks.

[Grime]

Some YSM 8 share oil with the engine. It could be a gasket leaking. Are you sure there is no water in the engine oil?

I've given up on my YSM 8. I do have a manual I could email you in PFD format if you like.

[hopefulsailor]

Yes, I would like for to email me the manual. PM me please.
Why did you give up on your YSM 8?

[Grime]

The Yanmar dealer had no idea how to repair my transmission. So I figured by the time it got rebuilt and the motor rebuilt I'd have more thousands of dollars invested than I wanted invested in the boat. So I got a 9.9 outboard and hung it on the stern.  My boat is up for sale now. The YSM 8 is still in the boat so the new owner can do as he/she pleases.

Yanmar is no longer making parts for the 8. When the parts supply is gone that's it. I would also think that some dealers will hang onto their parts supply for their customers.  Each dealer has a region and can not sell to you if you are out of that region.   

[Grime]

Be real careful with whom works on your transmission. If they pick up any kind of hammer get them off your boat before they use it. I feel that this is what happened to my transmission. It was working great until one of the boat yard personnel took a hammer to my prop shaft. I feel that this caused damage to the inside of the trans.

[ralay]

I have no idea what your problem is, but I'd be interested to hear an update if you figure it out.  Does your engine share oil between the engine and the transmission like Grime suggested?

[hopefulsailor]

No, I got in the manual and looked and the YSM8 transmission and crankcase are separate. I have no idea how it's getting in, the only thing I can think of is that the water is falling on top of the transmission dip stick, so I took some action.
I believe I fixed it. I replaced the plastic o-ring with a flat rubber gasket and I used closed cell foam to line the access panel. Let you know how it does.
While I was at it I changed the oil and transmssion oil and added the Lucus oil treatment. Great stuff immediately noticeable sound difference in engine for the better. Only thing is I motored to an anchorage and had oil on top and down the right side of engine, the side with the starter.