I had milky oil in the lower today when I changed the oil?

josh_scci · Jun 4, 2010

OK first post here sorry if I do something wrong:

The boat is an 87 Ozark if that matters
Motor is a 88 40hp Johnson

The boat did not run last year due to carb issues which I just got it back from having them rebuilt. he boat was my dads who passed away back in February so I got the boat but I don't think the oil in the lower has been changed since we have owned it over 15 years. If it has only once. Also when I pulled the screws there where no washers or O-rings of any kind.

So what should my next course of action be I already replaced the oil and both screws and washers. I am thinking it was because of the lack of seals on the screws but not sure. The prop spins freely and makes no noise at all. Any advice on what I should do?

lncoop · Jun 4, 2010

Re: I had milky oil in the lower today when I changed the oil?

You need to make sure all the o rings, gaskets etc. are in place then have the lower unit pressure tested. That will determine whether it's leaking. If it is leaking you'll need to assess the condition of the lower unit and go from there. Here's a very good sticky regarding your question. I'm sure there's lots of other info in the boards. Good luck and welcome aboard.
http://forums.iboats.com/showthread.php?t=207285

wilde1j · Jun 4, 2010

Re: I had milky oil in the lower today when I changed the oil?

Water is getting into the lower unit. One or more of the three seals is leaking, drive shaft, prop shaft and shift rod. Pressure/vacuum test to find the leaker(s).

kenmyfam · Jun 4, 2010

Re: I had milky oil in the lower today when I changed the oil?

If you have new oil and new seals in place and you see nothing leaking out then take it for a run and them drain a little out and see if any water got in there.
On another note, did you change out the impeller ???
Welcome to iboats.

older · Jun 4, 2010

Re: I had milky oil in the lower today when I changed the oil?

Wow, and I thought I neglected mine. I am working on my motor and had replaced the lower unit oil last year for the first time in the four years that I have owned the motor.

A couple of days ago I drained the oil before dropping the lower unit and almost no oil came out, just some milky krap which I know is water and oil mixing. I ordered the complete seal kit for the lower unit and quickly found out that removing the prop and drive shaft seals require a puller. The puller was rented at an auto parts store but then I just bought it outright as I figure if I'm going to do future maintenance I'll need it.

Good luck and take your time. I'll be dropping the lower unit this weekend for the second time to work on my original problem.

md95 · Jun 4, 2010

Re: I had milky oil in the lower today when I changed the oil?

I had the same problem with a 200 mariner. When i removed the prop there was fishing line wrapped around the prop shaft and appeared to have damaged the prop shaft seal. Replaced seal and haven't had any problems since.

josh_scci · Jun 5, 2010

Re: I had milky oil in the lower today when I changed the oil?

Thanks for the quick replies everybody it is appreciated.

But now I am confused I went to the sticky Incoop suggested and it says "Uncontaminated lower unit lubrication is generally tan to grey and mostly translucent" The oil that came out of mine was not totally translucent but it was a tan/grey mixture and I took this to mean milky because the new oil was green. There was no visible separated water or water drops anywhere. So was I wrong and it was just really old oil or do I still have an issue.?

Challenger84 · Jun 5, 2010

Re: I had milky oil in the lower today when I changed the oil?

I just changed mine this week and what came out was black smelly oil like fluids. Not see through.
No signs of water but it was a thick oil like fluid and the new stuff was see through and light green.
No problems was noticed

ezeke · Jun 5, 2010

Re: I had milky oil in the lower today when I changed the oil?

Oil mixed with water looks like cream. Worn out oil turns black and smells burned. If the unit is allowed to rest long enough, the water will settle to the bottom.

The nylon seals on the vent and fill plugs are often the source of the problem and should be replaced each time they are opened. A property of nylon is that it absorbs water and can expand to 30% or more, so they should be replaced rather than reused.

josh_scci · Jun 5, 2010

Re: I had milky oil in the lower today when I changed the oil?

Now I am really confused! So what color should the used oil have been if the sticky was wrong? Black just seems like a bad sign to me but as I am new to boat motors I have no idea. But as I said earlier they was no visible water in my oil it was a tan/grey color and somewhat translucent.

ezeke · Jun 5, 2010

Re: I had milky oil in the lower today when I changed the oil?

The sticky says "Water contaminated lower unit lubrication is milky looking and opaque. Uncontaminated lower unit lubrication is generally tan to grey and mostly translucent."

Oil that is simply worm out wil turn black. When agitated, oil that is contaminated with water looks like cream. It will be shaded by whatever color the oil was in the first place, plus age.

josh_scci · Jun 5, 2010

Re: I had milky oil in the lower today when I changed the oil?

Well I think I will put it on the lake and run it for a while and check it again after that since I just changed the oil and screws with new washers. Also this motor only has about 7 hours on it in the past 5 years we are crappie fisherman and we fish a small lake and only fish about 30 yards from the ramp so we don't do a lot of WOT or lon runs across the lake.

kenmyfam · Jun 5, 2010

Re: I had milky oil in the lower today when I changed the oil?

josh_scci said:
Well I think I will put it on the lake and run it for a while and check it again after that since I just changed the oil and screws with new washers. Also this motor only has about 7 hours on it in the past 5 years we are crappie fisherman and we fish a small lake and only fish about 30 yards from the ramp so we don't do a lot of WOT or lon runs across the lake.

Fine idea. Let us all know how it is after the trip.

I had milky oil in the lower today when I changed the oil?

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