How can water get into the outdrive oil?

[glennj3]

Changed my fresh water impeller last week and found the oil somewhat milky. It sat up for a couple of years on the trailer under a shed. Was used just a couple of times since the last change and once this past week for a test run.
I replaced the seals in the bottom of the lower unit about 3 years back, the upper seal would not hold good pressure and I should have changed it, but my mechanic forgot to tell me about it until I had it together again.
If the drain "o" rings are good, is there another way for water to mix with the oil?

 

[cptbill]

sometimes if there was dampness in there to start with you can end up with condensation. if it' not used a lot that would be my guess. also using an automotive gear lube will cause condensation

 

[Bt Doctur]

They are gaskets NOT O rings on the drain plugs

 

[glennj3]

It sat on the trailer under a shed for two years, monsoon rains here and water came up out of the woods and was all beneath my boat. Not high enough for her to float but made a lot of mud so I could not pull the boat out. I use oil I bought from the marine dealer, not auto.
Not "o" rings, I guess that is a matter of terminology, they look like flat soft "O" rings! LOL!, Wonder if I can get new ones alone?
I rode once in the lake so I can drain a bit of oil and see if there appears to be any water in it.

 

[flipbro]

It needs to be pressure tested. Your drive is sumerged in water so it sitting in the rain wont cause it.