Water in gearbox

[PhilfromOhio]

I have a Volvo penta MS4A 2.63:1 gearbox and there is water in the oil. I am hoping it is just an o ring. Hoping this won’t require a complete rebuild. Has anyone ever dealt with this?

 

[Scott Danforth]

Plenty of people get water in the gear box.

Sometimes it the drain plug seal

Sometimes it's a prop shaft seal

However the factory service manual has a process for trouble shooting

 

[kenny nunez]

Check the cooler on the rear of the transmission.

 

[apw30534]

I just did propshaft seals and O-rings in my DPS-A. It wasnt too horribly bad of a job but I did need to make bearing and seal drivers on the lathe... so that might be an issue for some.

 

[dubs283]

Agree w/Kenny. Oil cooler may have ruptured/corroded allowing sea water to enter transmission

Only other way water can enter is through a seal and if the transmission output flange isn't submerged its unlikely to occur this way