Oil loss from transmission

[daniel58]

My hydraulic transmission Borg-Warner 10-17-010 from about 1982 with Ford 4 cylinder 2712E engine.
Problem:
Low oil level in gearbox after running engine for 2 days over Biscay. Can it consume oil?
No oil spill under gearbox. Filled with engine oil to the right level (I did not have the proper transmission oil aboard).
In harbour: emptied oil with soak pump and filled up with correct automatic transmission oil
run engine for ½ hour -> got strange color:
maybe because of engine oil remains?
or saltwater in oil from leak in heat exchanger?
How can I see the difference between saltwater or engine oil mixture?
Test with Ohm meter: saltwater conducts well, oil does not! My mixture does not conduct at all!
Important question to YOU: What about a oil-saltwater mixture (Emulsion)? Should it conduct as well?
Does an oil saltwater emulsion separate after a time? (mine doesn't)
Any other ideas about my problem?

[Wotname]

Originally Posted by daniel58

My hydraulic transmission Borg-Warner 10-17-010 from about 1982 with Ford 4 cylinder 2712E engine.
Problem:
Low oil level in gearbox after running engine for 2 days over Biscay. Can it consume oil?
No oil spill under gearbox. Filled with engine oil to the right level (I did not have the proper transmission oil aboard).
In harbour: emptied oil with soak pump and filled up with correct automatic transmission oil
run engine for ½ hour -> got strange color:
maybe because of engine oil remains?
or saltwater in oil from leak in heat exchanger?
How can I see the difference between saltwater or engine oil mixture?
Test with Ohm meter: saltwater conducts well, oil does not! My mixture does not conduct at all!
Important question to YOU: What about a oil-saltwater mixture (Emulsion)? Should it conduct as well?
Does an oil saltwater emulsion separate after a time? (mine doesn't)
Any other ideas about my problem?

Oil / saltwater emulsion does not seperate over time. At least not in any normal sense of the word. I have some sitting in a bottle and after several years, maybe 1% has separated.

I haven't tried a conductance test on it but I will tomorrow since you have asked the question however I am fairly sure it won't. AFAIK, each water droplet is separated from the next one by a layer of oil thus preventing reasonable conduction.

As for colour, if you still have the engine oil, just mix a small amount with some ATF to get an idea of what it would look like. Emulsified water / oil is normally opaque and 'milky' looking.

[tkeithlu]

Daniel, the information you've supplied is confusing, or at least, not clear. Let's go back to the beginning.

If the oil level in the transmission is going down, the probable cause is old oil seals in the transmission. Given 1982, the seals are highly suspect.

If the transmission oil looks like a milkshake, yes, you've got "oil in your water." If you've got a heat exchanger for the transmission, that's the likely source of the water.

Take those two starting points, and chase it down. Drain as completely as you can, and load up with the right amount of transmission oil. Take plenty of spare oil with which to get home when the tranny quits, and go motoring. Shut it down and check the oil every hour or so. Dropping level? Probably the oil seals, go home, remove tranny, take to shop. Milk shake? Go home, pull the heat exhanger, test it for a leak.

Forget the conductance. That's not really going to help you solve this one.

Happy sailing. By the way, I've been there with the seals failing.

[tkeithlu]

Oops. Just thought of another possibility. You could be losing transmission oil through a heat exchanger leak. If the oil level is going down and you have a heat exchanger on it, test that before you go to the considerable trouble of pulling the tranny.

[Lancerbye]

Had the same problem a year ago. I have a dual oil cooler. The transmission side started leaking resulting in oil loss and salt water intrusion into the transmission oil. Changed the cooler and solved the problem. Not cheap but was needed.

[Siberian Sea]

You transmission gear pump produces about 140 psi oil pressure. This oil flows through a heat exchanger and overtime the heat exchanger might develop a small leak between the oil side and the seawater side. Because the oil side has much more pressure then the water side the oil is leaked out into the cooling water so you see no oil in the bilge

[Disailor]

Two thoughts: 1) When trans cools water is sucked in & 2) Doesn't engine oil deteriorate the trans seals?

[auskiwi]

Had the same problem with same gearbox and engine in a previous boat, was heat exchanger leak that did not have a zinc, replaced heat exchanger, made sure it had provision for zinc, washed gearbox out well so no more water contamination, ran perfect for years.

[daniel58]

Thank you very much to everyone helping me. I have changed the heat exchanger, and the problem seems to be solved.