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bf50- milky oil

D

dark_star

Regular Contributor
Just drained the lower unit and oil was white/grey in color.
what is the most common failure leading to this situation ?
changed the gear oil, will check in a week and if necessary
make the repairs ...
is prop shaft seal a likely problem ?
 
Prop shaft seal is usually the culprit. When you changed the gearcase oil, did you remove the prop and thrust washer to check for fishing line and other junk that can get in there? Whenever you change your oil - every 100 hours, or every season - you should remove the prop, inspect the prop shaft, seal, and thrust washer, re-grease everything, and put it back together with a new cotter pin.
 
If the motor has a lot of hours, the shift shaft sometimes develops wear near the shift boot and messes up the boot.

Be sure to change the washers on the drain screws. If reused many times, they can let water in also. Ideally, they should be changed with every gear lube change.

Mike
 
Just a thought, is it possible for water to drain from the engine compartment down into the lower unit ?
reason i ask is that I had a fair bit of water pooling up while fixing the telltale spray.
or is the lower unit completely sealed from the engine ?

Thanks
 
It turned out to be drive shaft seals, both prop shaft and shift shaft were ok
under a pressure/vacuum test.
anyway the motor is back together and i can go fishing !
 
dark_star,

Great to hear that, and a good lesson learned. Do you have an extension case on that engine? Seems I recall that Honda has had some serious issues with the drive shaft in the extension casings, especially for the 30" extension.
 
chawk_man said:
dark_star,

Great to hear that, and a good lesson learned. Do you have an extension case on that engine? Seems I recall that Honda has had some serious issues with the drive shaft in the extension casings, especially for the 30" extension.
Click to expand...

No extension case, standard shaft length... Just out of curiosity,
How long could you get away with running a motor with water intrusion
in the lower unit without serious damage ?
 
Darned if I know. Fortunately, I've never had the misfortune to have that happen.

Hondadude or jgmo may have had some experience with customers in that arena.
 
well, it turned out this wasn't the problem as i am still getting milky gear oil
in the lower unit.
i spoke with the mechanic and he pressure tested on the bench and found no leaks ??
any other idea's ?
 
Have him pressure test it again under water. Check for small bubbles. Who knows what happens when things start vibrating and are loaded.

I have found, on anything but new lower units that have an issue with one seal, I just change all the seals while I have everything apart. It does not take that much longer and minimizes comebacks like this.

Hopefully, he put the seals under the waterpump in correctly. They should both be in the same direction (not back to back like most seals like this get installed).

Mike
 
well, still fighting the same problem...
hate to pull the lower unit and go through same process again.
anybody got any idea's ?

another question, i've been running the motor like this for 5 months
with no obvious problem.
as long as there is no actual water present, is this a serious problem ?


Thanks
 
If you are checking right after the motor was running you might see " milky looking oil " caused by tiny air bubbles.--------------Let it sit for 2 days and check it then.---------------------No bubbles= no troubles.
 
Is your mechanic vacuum testing the gearbox as well as pressure testing? The seals can leak in either direction.
 
Update May 8/11

After fighting with this problem for nearly a year, i went to change the lower unit gear oil
yesterday, and it was clear ! in fact almost as clear as new stuff.
i'm pleased , but can't quite figure out why this happened ?
 
Sorry to pain you all once more, but this is ongoing.
I spoke with the mechanic and he advised Honda's are notorious for corrosion
and rather than take a chance at breaking something on an older motor,
simply check the gear oil and replace it more often.
I should mention the engine is 1999 model with approx 3500 hours on it.
Is this reasonable ?
 
Personally, I would be inclined to get to the bottom of the problem one way or the other. 3500 hours is a good long run, but these engines should be good for 5000 hours plus if rigorously maintained. If push comes to shove, consider purchasing a rebuilt lower unit. I assume they are available from a rebuild shop. Mike or Chris would likely know.
 
I'm confused by your posts. In May you wrote that you were "pleased" with what you found when you "went to change the gear oil". So now it has water intrusion again?

I don't think you are fighting "notorious corrosion" or excessive age... or hours. I believe your problem lies with your mechanic. These units seal right up, and stay that way, using proper parts, tools and procedures. That is, of course, as long as the outboard is not left soaking in salt (or fresh) water for long periods and if the scheduled maintenance is done correctly.

They DO NOT last very long when water is allowed to enter the transmission again and again.

And, "inspect and change the oil more frequently" is just plain bogus, COP OUT, advice in my opinion.

Your mechanic can't get it done and has given up on you and your equipment. It's time for you to give up on him.

Sorry if that sounds blunt but that is my answer.
 
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