How milky is too milky lower unit oil?

[alnt]

All,

I've just bought a used boat, and started to service the lower unit on my way to a new water pump impeller+housing, spark plug wires, etc. When I drained my lower unit oil (1982 Johnson 115TLCN), the oil was mostly black and smelly, just like I like it. However, toward the end of draining, there was some milky oil coming out. So there is a bit of water in there, but when should I get concerned? I plan to refill, take it out for a day and re-check it. Do I need to completely drain it? Any other suggestions?

Just a note - the two drain plugs were not very tight when I pulled them. The seals were on the plugs, and there were no obvious leaks around the plugs, but it barely took any force at all with the flathead screwdriver to get them loose.

 

[kenmyfam]

Re: How milky is too milky lower unit oil?

Put new gaskets on the screws. Go for a spin and check again. However if the oil get's milky in the slightest it is time to solve the issue. It will not get better...only worse.

 

[14ftgrumman]

Re: How milky is too milky lower unit oil?

Any milky is too milky.

 

[deviljohn]

Re: How milky is too milky lower unit oil?

I ran a 30 hp yammie w/ milky oil for 5 years in saltwater...changed more often than normal...and i don't mean just a little bit of water..I mean milky chilky gooey booh hooey...so eventually the lower unit began to break down and now reverse gear is shot.....

but in lieu of what it may cost to have a marine mechanic replace the seals in the Lunit,,,erghhn hate to know what that cost...problably more than a used lower you can find on ebay...so with that said, i'd saya little goo will be alright depending on the demands you put on her...salt vs. fresh...run a lake or drag thru salt flats....etc...

i wouldn't be too worried about a little cream...just change every season, or twice every season...roll on until you hear that evil grinding.........perhaps a dab of some Lucas oil stabilizer...thoughts?????

make sure you have an adpater and pump to fill the unit from the lower fill plug.....goo out the top, then seal top, plug bottom and roll on....

ps: i ve got a 1984 140 hp 20" shaft Lunit in my shop if ya need one. Should fit a 115 V4 in same age range, but I would keep this as a backup if and when yer's kapoots..

 

[jtexas]

Re: How milky is too milky lower unit oil?

I know guys that ignore water in the gear oil. And, that marine oil will tolerate some water without breaking down too much.

I guess, if you have to pay somebody else to do the seal job, I can understand trying to push your luck.

But in my experience, and I say this as one with no formal mechanic training whatsoever, it is within the scope of a determined do-it-yourselfer with some basic tools and a factory service manual.

Doing it yourself changes the cost-benefit analysis in a big way (and I DO have formal training in the cost-benefit analysis arena).

do what kenny says, it'll probably solve the problem anyway.

Then, change the oil annually, on a schedule. I like to do mine in the fall before the first hard freeze, in case water gets in there I don't want it cracking the gearcase open.