Water in lower unit

[Roady1]

I think this is a common problem but my question goes a little deeper. I found water in my lower unit on my Merc 3.0. Now I have read about the presure testing to find out what seal is bad, and thats no big deal. My question is, what gets damaged by the water being in there? I have a loud clunk, almost a crack of metal peices banging together. This even happens without the drive gear engaged. <br /><br />My guess is that it's a bearing ready to fail but I'm not sure. What parts would need to be replaced in this situation.<br /><br />Thanks for any help.

 

[Boomyal]

Re: Water in lower unit

Water does not lubricate. Marine gearoils can swallow a small amount of water, disperse it and continue to lubricate, beyond the limit ya start grinding metal. You just need to disassemble it and inspect the components. Do it before anymore damage is done.

 

[Roady1]

Re: Water in lower unit

Thank you for the reply. <br /><br />One more piece of information if it means anything. When I drained the oil from the lower unit, (the drainhole down by the prop) That oil was water free. The milky oil was up in the reservoir located in the engine conpartment. Does that give you a hint to which seal is bad?

 

[cuzner]

Re: Water in lower unit

Did you notice any meatal chips on the drain plug? they are magnetic,even a little can mean problems.<br /><br /><br /> Jim

 

[tommays]

Re: Water in lower unit

the upper and lower have a small oil passage between them so what ever is in one is in the other in some amount<br />i have to say that is the first time i have heard of the tank getting milky i have to guess that a lot of water would have to be getting in to push its way into the tank<br /><br />tommays

 

[Roady1]

Re: Water in lower unit

When I drained the oil from the lower unit, I did see some metal in the oil, but the oil was free of any water. I mean it was as black as black can be. I removed all the white oil from the reservoir in the engine conpartment and replaced it with fresh oil. Ran the motor for 1 minute and shut it off. The reservoir was full of milky oil again. The lower unit oil was still black. I'm at a loss.<br /><br />I guess my main question is, with metal in the lower unit oil, knowing that water has got in somewhere, what parts do I look at replacing. The drive shaft? Bearings maybe? I have never worked on a I/O before so I looking for a starting place to inspect to look for the damaged pieces. What is the most likely piece that is damaged when water enters the lower unit?<br /><br />Thanks again everyone.