Lower unit fluid

[jmg]

Last Fall I posted that when I drained the lower unit on my 1997 30 hp Evinrude, I noticed some significant milky streaks in the fluid. This upset me, since I had only used the motor 4 times in 2011, after buying it from a private seller in April 2011. As usual, I thought I had really gotten screwed on another purchase that had seemed like a great deal when I had bought it.

This fluid issue has been bothering me all Winter. What should I do with it this Spring? Should I just run it a couple of times, drain it again and assess the fluid or do I need to take it somewhere to have it taken apart and checked? What would need to be done to it-new seals, etc? If so, how much, ballpark figure, would I be charged? Not a good year to have to spend extra on it, but I don't want to wreck it. Other than that, I really liked the motor. Any ideas will be appreciated.

10 Weeks till the opener-can't come soon enough!!

[CAMAN]

I'd suggest bringing it in now and have them test it. Doing it when everyone else is will just make you wait...and wait...and wait...when you're itching to get on the water.

I'd say a good estimate would be $100-300 to replace the seals, depending on where you go.

If you really can't afford to spend that on it right now, you won't hurt it if you just keep an eye on it and replace the lube if it looks to be getting milky.

It could also be a very simple and inexpensive repair, maybe the seals on the drain/fill plugs may need to be replaced. Or it is just condensation inside and draining and refilling after the first couple times out could get all the moisture out.

[jmg]

Thanks for the info, Caman. I think I will use it a few times, drain it and see what's going on. By that time, the repair shop crowds will probably have died down so the repair wait time wouldn't be as bad.

Hope it is something simple!

[SkunkedAgain]

CAMAN is right on. I wouldn't run it a few times and then bring it in. You are getting water in your lower unit right now. 9 times out of 10 that means you've got old/cracked/hard seals and gaskets that aren't doing their job. While it will cost a couple hundred $$ wherever you go, that's all for the labor. It's a pretty easy repair to do yourself if you've got the time and a repair book. It's removing screws and bolts.

However, I wouldn't wait to get this thing fixed. Once the snow really starts to melt and so does the ice, that's when everyone takes their motors in to be fixed. Some people get their motors back in time for opener, some don't. Once the repair shops catch up on those "getting-ready-for-spring" repairs, they get the deluge of motors that died pre- and post-opener. Right now, meaning this week, is the time to get that motor into the shop BEFORE the rush!

The nice thing about your repair is that it's not a mechanical problem, like a bad powerhead or lower unit. Bad seals happen to everyone. You didn't get screwed. It's similar to having bought a car with bald tires. Put some new rubbers on it and the thing is ready to go.

[mamohr686]

I would have had it fixed right away. Water in the lower unit can rust/pit your bearings, and if it has a lot of water it can actually crack your lower unit when the water freezes and expands. I also wouldn't have blamed the previous owner. It can happen if you only fish out of the boat one time. The most common cause is other fishermen throwing fishing line overboard, and it gets wrapped up behind your prop and destroys the rear seal/gasket.

[hydro]

It could also be as simple as the gaskets under the fill/drain screws, since they are often the culprit for a little water in the gearcase.

If it were mine, I would pull the prop and check for any evidence of line wrapped up on the prop shaft. If you cannot see anything obvious, replace the prop, get some new screw gaskets, fill it with oil and take it out for a test run. Let it sit for a couple of days for any water that got in there to separate, then pull the drain plug to see if it runs clear or milky. No sense spending $300 for a rebuild if it was just a gasket, or if the problem is there then it's time for a trip to the shop.

[FBMH]

Take it in!

I had the same problem last year with my 1995 25hp evinrude. I noticed milky streaks in my lower unit oil. I took it in, they told me the seals were cracked and they replaced them. $127.90 inlcuding labor, so not to expensive. Havent had a problem since!

[whos_on_first]

I have a 96 evinrude 25 hp and drained it for the first time last night and it stunk bad...almost smelt burnt. I've had it for a couple years, and have only had it running maybe a dozen times, but I'm not sure the previous owner changed it regularily. No milky streaks though. Should I be concerned? Hopefully it's just old fluid in need of a change...

[jentz]

I do quite abit outboard motor work,The motor with the milky streams comming out.That one I would drain,replace the nylon washers on the drain plug screw and the top air vent screw.Refill run it 2-3 hours drain and inspect.If its yet milky its probably a seal.

The stinky gear oil is no worry they all stink, some more that others depending on how long the gear oil has been in it.

[Tom7227]

I am curious to know how they test for the bad seals. I am also curious about the 'streaks' of milky oil as opposed to the entire amount of oil. I don't want to short circuit anyone's advice, just curious about these two things.

Thanks

Tom

[CAMAN]

The streaks of milky oil is caused by the water settling to the bottom when it sits. When you drain it the milky oil will come out first, then the clean stuff will come out, as the clean stuff comes out, it will grab and pull out some of the milky stuff that is left just at the bottom of the drain plug and make the streaking oil described.

Lower unit seals are usually tested by applying a slight vacuum and/or air pressure through a drain/vent plug and seeing if it holds vacuum or pressure.

[jentz]

I am curious to know how they test for the bad seals. I am also curious about the 'streaks' of milky oil as opposed to the entire amount of oil. I don't want to short circuit anyone's advice, just curious about these two things.

Thanks

Tom

Pressure testing for leaky seals,You can do it your self with a pressure guage that has a rubber tip and a air passage with purge valve,Blow air in tothe drain hole, 15lbs hold the guage and see if it drops,The ole soapy dish soap water will show where leaks are.Streaky milky oil is just small amounts of water in there droplets.Dont ever go beyond 15 lbs ppressure you stand a chance of blowing seals

[boatfixer]

What I prefer to do when pressure testing is to go up to about 8 psi, let it sit momentarily then rotate prop shaft, drive shaft and operate the shift shaft. I'll then increase pressure to 10-12 or so, same thing then up a little more but no more than 15. The reason for moving things us obvious. The reason for starting with lower pressures is because its possible to "puff" the seal lips and give you a better seal between the shaft and seal lip.

It shouldn't stop at pressure testing though. Remember, you are getting water in and a vac test should also be done. It is possible to have water coming in and yet it holds pressure.