Water In Lower Unit Oil

[RV Sam]

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.

 

[robert graham]

If your pressure tests are correct then I don't have any idea how the lower unit leaks???...when you say, " crappy looking oil", what exactly do you mean?.... I change my lower unit once a year and the oil does develop a darker/black color by the end of the season, but putting a drop on the tip of my finger I can see it's still clean/clear, but with a darker color....water contaminated oil with be a " milkshake/creamy look.....Also, do you have any metal particles on the lower drain plug magnet?...

 

[bruceb58]

Do you replace the seals under the drain and fill plugs every time you change the gear oil?

 

[RV Sam]

Thank you guys, Yes seals replaced on the plugs.
Mike shake creamy look it is but no metal that I saw.
What do you guys think of the oil from the year before still having enough left on and mashed in the gears to mix in with the new and cause this ?

 

[robert graham]

I would doubt there would be enough oil/water mix from previous to contaminate a fresh oil fill back to " milkshake" status....but if the pressure test is good then how can it leak?....

 

[RV Sam]

That's not what I wanted you to say, lol.. Does Suzuki give a Max PSI for a pressure / vacuum test ? Just trying to figure this out. Of course there is very little to no pressure in that sealed unit anyway.

 

[99yam40]

as the oil and metal heat up and expands and then cools and shrinks back up there will be pressure changes, but not much IMHO

I would change oil again making sure to flush out as much of the contaminated oil and run it to see if it happens again if it passes the pressure testing.
Was the lower unit drained when you tested it? it should be from what I understand

 

[RV Sam]

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 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.

 

[99yam40]

I do not know if it was a good idea or not, but I have filled a contaminated lower unit with new/clean automatic transmission fluid I had sitting on a shelf for years to help rinse out the unit.
Left the drain plug out over night to make sure as much as possible had drained out before filling again with proper lube

 

[bruceb58]

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.

Just to make sure, I would see what the manual says about filling it.

 

[RV Sam]

Update on the water in the lower unit on my DF150
All is well, took her home yesterday and the lower unit oil is as good as the day I put it in. Guess the problem was some "bad" lube was still around the gears from the bad seal the year before and contaminated the oil last year.