Water In Lower Unit DF150

[RVSammy]

Hi Guys. 2007 DF150.,. Last fall after pulling from slip I had water in lower unit oil. Did a pressure and vacuum test and discovered one of the seals under the nut on the drive shaft was torn. Replaced and held pressure and vacuum.
Pulled the boat this year, crappy looking oil in the lower unit. It was a water / oil mix as I just had the boat running 2 hours before and no time for it to separate. Yanked the lower unit off and back into my work area. Pressure test at 6 lbs and 13.8 lbs. Held for 36 hours before I let it off. Pulled a Vacuum at 12” lbs and it held for 24 hours before I let it off. Back to pressure at 10 lbs and still there 24 hours later. Every now and then as I would walk by I would turn the prop and drive shaft. No drop. I would wiggle and shift shaft but not actually put in gear. Not sure if I could without drive turning. I had no drop, not even the thickness of the needle on the gauge.
Any thoughts please and thanks.

[Harper]

Well, I read this last night .... it's a puzzler. You've already done all that I would have suggested. The only thing I can suggest at this point would be that it has to be operating, shafts turning at an operating RPM (rather than being turned by hand occasionallly) when the water intrusion occurs. I guess if it were me, I'd go ahead and replace every seal at this point, or at least, start with replacing the prop shaft seal. I don't know, but had the thought that there might be a crack in the housing. I don't know if it's possible that a housing crack could leak only when put under stress of normal operating conditions and pressures. But like I said, it's only grasping at straws at this point.

[RVSammy]

Thank you Mike for the time to reply.
I didn't want to say this because I didn't want this in anyone's mind until I got a few replies, but here goes, lol...
What if, just if, all the oil / water mix from last year didn't drain out. Now put new oil in a blender ( lower unit ) for hrs and hrs and see what happens. I did a test on 1 ounce of gear oil and you do not need much water to turn it bad after you stir it for a few minutes.
The boat is slipped for 6 months and I don't really want to pull and take home for a "test" after a week / month.
Thank you.

[catacom225]

Gear oil

Sammy, I was thinking along those lines. To completely remove all traces of water you would have to pull it to pieces and wipe clean every part
It may take several oil chances to remove water or run some kind of cleaning solution through it

[Moonlighter]

Two thoughts on this.

One, have you checked and replaced the washers under the 2 oil drain holes? They can get deformed and we usually replace both of them every time we replace the oil.

Secondly, i agree that there may have still been some water left in there from the original problem.

I recall having a similar problem many years ago on an old Johnson outboard and we were told to flush the gearbox with metholated (white) spirits. The metho absorbs water so as you flush it through, it picks up any globules of water and takes it with it as it drains out. We then gently blew compressed air through the gearbox to help evaporate the remaining metho, refilled, and never had another problem.

[artdf175]

I can agree with making sure you change the washer on the drain and vent screws every time you remove them
the one on the drive shaft can get cut up if you have ever had fishing line in the prop. almost an automatic to do especially if you use tuff line..

there is one more to inspect. if you have had the lower drive shaft open for any reason. I hit the top of a sunken post, just nicked it and bent the lower shaft.
when the dealer put it back together there is a large "o" ring that fits between the outer housing the shaft housing that slides in.. evidently it did not go back in correctly.. looked fine for some time then one day just leaked large amounts of oil out.. only discovered after he put an air pressure hose to the vent.. how much pressure don't have a clue.. but the oil did flow out with pressure

art..

[Solarman]

Another thought while checking for possible leaks, when adding pressure to look for leaks, rotate the drive shaft, shift the gears, and spin the prop shaft. Look around all the seals, under water pump plate, around shift rod, as well as prop shaft seals while moving and under pressure.
Expansion and contraction from operating temperatures are when oil leaks, and water enters (not very high pressure).

Good luck, post back if you find anything.

[RVSammy]

Thanks much guys for all replies.
Update. Added gear oil to correct level a few days ago. Put back "old" washers as I did not go to boat shop to get new ones yet as I was waiting to see what else I needed. I turned the prop and few dozen times and same with drive shaft. Drained the oil. Not being here to see it you will not believe me. The oil was milky and very much unlike it was before I put it in. I know your thinking I drained the old oil without tipping the drive in a position so it all drained out, nope. Before this I had it tipped in a position so the drain was the lowest part of the drive and left it for a few days. Which gave me another ounce or so. So without a rinse as mentioned above by Moonlighter I am guessing enough of the water mix oil was still there.
I'll have to look into a rinse for something that will remove all traces of water and not hurt the seals. I know that 99% gear oil and 1% water may not be a problem but I need a proper reference point for future years so I know if all ok, or another seal let go.
FYI. This is what I discovered about plug washers.
I have 3 plugs, lower for draining, top labeled Oil Level and one above it called Fill. So I am figuring Suzuki ( this model year anyway ) does not need to be filled from the bottom drain hole with a pump on the bottle as we have done for years. Take out top 2 and fill from upper top most hole until oil comes out of the one labeled Oil Level. Nice feature.
Anyway, I removed the Fill plug, this is the first time it was taken out as I never used it. Set up the air line to the this plug hole now and did a vacuum test. Remember old washers on the other 2 still. Held vacuum for hours. I started to play with the Drain first and then the Oil Level plugs. ***. I had to turn a few turns and thought the plug would fall out before I lost vacuum. Set up for pressure test. Did the same, had a few turns before I started to lose pressure. I will still replace them as they have been in and out more then the normal. But, I feel if you get a leak here something has gone really really wrong. Wish I had an extra so I could double them up and see what happens.
Thank you guys and you all have a Merry Christmas and a Happy New Year.

[boashna]

put some drops of water in oil and see how fast the oil changes color for reference also temp will cause the gapes to get larger so it ay be sealed at 50f but not at 100 f