Milky gear oil and two holes?

khelhelou

Petty Officer 3rd Class
Joined
May 26, 2012
Messages
81
IMAG0734.jpg

1. ok i understand that milky gear oil means theres water leaking into my lower unit, but how harmful is it. I mean i just changed the oil and ordered a lower unit seal kit, but im taking the boat out this Sat, and the seal kit wont be in until Mon.

2. Also how can i test the pressure myself, i dont trust dealers...

3. Lastly if you look at these next three pictures ( i took three because i couldnt really get a good focus on what im trying to explain) what are those two holes to the left and why were they drilled there?IMAG0735.jpgIMAG0736.jpgIMAG0737.jpg

Thanks!
 

boobie

Supreme Mariner
Joined
Nov 5, 2009
Messages
20,826
Re: Milky gear oil and two holes?

You should stick to one post.
 

adamh1281

Seaman Apprentice
Joined
Jul 26, 2011
Messages
33
Re: Milky gear oil and two holes?

most will say first replace the seals on the fill screws. then see if that fixes it. I think it depends on how much waster was in it when you drained it. did a bunch come out? mine was milky but no water separated out to the bottom. I ran it like that, doing fluid changes every other time til the end of the season. Yesterday I made a pressure tester, and it kept pressure of about 20-30 psi for half an hour, so my next thing to do is to pressurize it and put into water to see if I can see any bubbles. I've also read it may take several fills to get all the water out. so there's my 2 cents. hope it helps...by the way, I'm not a mechanic.
 

khelhelou

Petty Officer 3rd Class
Joined
May 26, 2012
Messages
81
Re: Milky gear oil and two holes?

most will say first replace the seals on the fill screws. then see if that fixes it. I think it depends on how much waster was in it when you drained it. did a bunch come out? mine was milky but no water separated out to the bottom. I ran it like that, doing fluid changes every other time til the end of the season. Yesterday I made a pressure tester, and it kept pressure of about 20-30 psi for half an hour, so my next thing to do is to pressurize it and put into water to see if I can see any bubbles. I've also read it may take several fills to get all the water out. so there's my 2 cents. hope it helps...by the way, I'm not a mechanic.

It was just milky with no water, but ALOT came out...how would i go about pressure testing it?
 

adamh1281

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Jul 26, 2011
Messages
33
Re: Milky gear oil and two holes?

look, please don't hold me responsible for the things I recommend. I am a chiropractor and chemist, but I am very mechanically inclined. I am replying mostly because no one else has given you any help here. So please search on this because this is a common problem that many have had. I just feel like even though I have a common problem, sometimes I like to get someone else's opinion. So here it comes... Last week I made a pressure tester out of a lower unit fill pump, hose clamps, bicycle inner tube valve stem, and a bike pump. I used the screw in oil filler and hose which I cut, and ran it to a bicycle valve stem that I cut the inner tube off of. I used a bicycle pump to pump air into the lower unit. I screwed the plastic oil filler thing into the top screw hole, and used the regular drain plug in the bottom. I pumped probably 25psi into it and listened for a leak, I didn't see or hear anything. so I got some soapy water and brushed on over the rubber seals, no bubbles. Now next I will pump about 15 or so psi into it and dunk it into some water and look for bubbles. I'll probably use a garbage can. then I'll turn the drive shaft to see if that causes bubbles. If not, I'll just add more lower unit oil and check it after a few outings. If there was plenty of oil that came out, when you drained it, like mine, the leak is probably not that bad. good luck, and search those forums.
 

kfa4303

Banned
Joined
Sep 17, 2010
Messages
6,094
Re: Milky gear oil and two holes?

Hi khelhelou. The milky oil is definitely NOT good. That being said, if you refill it with fresh oil you "should" make it through your up coming trip, but there are no guarantees. At the very least, I would take more gear oil with me to refill the lower unit while out on the water, if need be. Afterwards, you'll definitely want/need to reseal the LU to prevent any future water intrusion. As for the two small holes in your second pic, they are NOT factory and should definitely NOT be there. It looks like a previous owner was trying to drill a hole(s) there and thankfully stopped before they were successful. I would fill them in with JB weld epoxy putty, or have a professional aluminum welder repair it. The other holes are the normal DRAIN and VENT openeings. New fresh oil should be pumped into the lower DRAIN hole until it comes out of the upper VENT hole. This bottom up filling method is done to force out any air that may be in the gearcase. Once the oil comes out of the upper vent hole, replace the large flat head screw and repeat for the lower, DRAIN screw. Here's a link that can walk you through a basic reseal job on a vintage OMC motor.

http://forums.iboats.com/showthread.php?t=277190&highlight=lower+unit+seal+kit+installation
 

khelhelou

Petty Officer 3rd Class
Joined
May 26, 2012
Messages
81
Re: Milky gear oil and two holes?

Hi khelhelou. The milky oil is definitely NOT good. That being said, if you refill it with fresh oil you "should" make it through your up coming trip, but there are no guarantees. At the very least, I would take more gear oil with me to refill the lower unit while out on the water, if need be. Afterwards, you'll definitely want/need to reseal the LU to prevent any future water intrusion. As for the two small holes in your second pic, they are NOT factory and should definitely NOT be there. It looks like a previous owner was trying to drill a hole(s) there and thankfully stopped before they were successful. I would fill them in with JB weld epoxy putty, or have a professional aluminum welder repair it. The other holes are the normal DRAIN and VENT openeings. New fresh oil should be pumped into the lower DRAIN hole until it comes out of the upper VENT hole. This bottom up filling method is done to force out any air that may be in the gearcase. Once the oil comes out of the upper vent hole, replace the large flat head screw and repeat for the lower, DRAIN screw. Here's a link that can walk you through a basic reseal job on a vintage OMC motor.

http://forums.iboats.com/showthread.php?t=277190&highlight=lower+unit+seal+kit+installation

thats what i thought because they do not look factory...but someone else told me there the leak hole for unburnt oil?? if i seal them where would the unburnt oil get out from?
 

adamh1281

Seaman Apprentice
Joined
Jul 26, 2011
Messages
33
Re: Milky gear oil and two holes?

unburnt oil? wow. um... do you mean the 90 or so weight gear oil inside the lower unit gear case? It is high temp lubricant that should never burn in the first place. It is a closed system like the differential in a truck... Or do you mean 2 cycle oil you add to your gas? either way No, and NO. there should be little unbunt oil at all. your 2 cycle engine should be burning almost all of the combustibles, and the little that remains leaves through the exhaust that's the hue on the water, and the smell of a 2 stroke. Usually black sooty water comes out of the exhaust form the prop or exhaust port you can see when running on land. we all have to learn somewhere, but the functioning lower unit of an outboard may not be a good place to start. At least it's an old motor. There are some tricky things about the lower unit that can lead to trouble if we tinker around, I've heard horror stories about people loosening bolts (philips head) that should not be loosened, or trying to remove the lower unit etc. It may be worth it to have a shop look at it. I hope I haven't offended. And JB weld the holes IF were drilled, that's the first place to start.
 

HighTrim

Supreme Mariner
Joined
Jun 21, 2007
Messages
10,486
Re: Milky gear oil and two holes?

What motor are we talking about here? That would help.

IM not sure what model we are referring to, but those small holes may be drain holes for the gearcase. If you fill them in, spent cooling water will have nowhere to drain. Now winter time comes, that water sitting in your gearcase now expands when it freezes and cracks your gearcase. I have come across many gearcases where owners fill in the drain holes mistakenly and crack their gearcases. Seeing black goo dripping from these holes is completely normal. Nature of a 2 stroke, not all the fuel oil mix gets completely burnt, and exits here mixed in with the spent cooling water.

Im not saying that is what they are for sure, but look into it before proceeding to fill them. If the are drilled into the exhaust cavity, they will not harm anything. That is where the drain holes are drill into.

Another problem is those pesky little mud daubers. They build nests in the drain holes, restricting the spent cooling water from exiting when you pull your boat out of the water. This is an often overlooked maintainance item. Should especially pay attention to it when doing gearcase service such as an impeller. I use a very long drill bit to bore out the nest. They are much stronger than you would think, it takes quite a bit to drill through them sometimes.
 

AlTn

Commander
Joined
Mar 9, 2010
Messages
2,813
Re: Milky gear oil and two holes?

those Canadian mud < dirt > dobbers sound like a determined lot...do they work their way up the exhaust snout, or the exhaust relief holes?...their southern cousins seem content to settle under decks, roof soffits, and the like
 

HighTrim

Supreme Mariner
Joined
Jun 21, 2007
Messages
10,486
Re: Milky gear oil and two holes?

They seem to like the very small diameter holes, such as those tiny drain holes, as well as the tell tale holes. Im not sure if that is the exact name of the creature that builds them, but is what I was told.

I am working on a gearcase right now where the nest is the entire cavity of the drainage cavern. It is almost hard as cement.
 

khelhelou

Petty Officer 3rd Class
Joined
May 26, 2012
Messages
81
Re: Milky gear oil and two holes?

My motor is a 1966 Evinrude 60hp Sportfour
 
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