Transmission smoke

[brianc629]

I was looking over my Westerbeke 40 engine with an LED flashlight while the engine was running. I happened to notice a faint wisp of white smoke coming from the oil breather tube on the Paragon hydraulic transmission (PM10L). The smoke is present as soon as the engine is started, and it does not seem to matter whether the tranny is in R, N, or F. I could not detect any odor from the smoke either.

I don't know if my transmission has done this for a long time, or it just started, but it took the strong LED light beam for me to notice it.

Does anyone have any ideas as to what may be the cause?

Thank you!

[paulajayne]

Not smelling, then I would guess misting oil and not smoke.

[DougR]

It could be water vapor exiting the gear as the gear warms up. If there is a water cooled cooler for the gear oil it might have a pin hole in it, allowing water into the gear oil.

DougR

[brianc629]

Thank you for the suggestions. Since the smoke or mist appears immediately after starting the engine, I don't think it could be steam. And the smoke it not hot either.

I had not considered, and am not really familiar with, the concept of misting oil. Is this something common with hydraulic transmissions?

Thanks!