When I winterized my boat and changed the drive oil in Oct there appeared to be 1 -2 ounces of water in one drive (a little hard to tell it seems with using RP oil). As a result of this I did pressure and vacuum tests, both of which held 15 lbs +/- for 24 hours? This would indicate to me that the seals are in serviceable condition? If this is the case, how does water get into an apparently watertight drive? It does not appear to be getting throught the one way driveshaft seal inside the bellows as there is no rust, condensation, or any evidence of water getting into the bellows?

What gives?

Any fishing line on the propshaft? Is the grease still intack between the inner and outer propshaft seals? Are you runing a drive shower? During the psi tests, did you rotate the input and propshaft to see if it had an affect?

Normally a psi test will find a leak, but in this case it seems to have come and gone.
It this a dwp lower? On some there is a plug in the front of the case to seal it off from the water passage. At speed it could be leaking. I have heard of people having issues with the plug sealing.

Dick

No, no fishing line or foreign matter of any kind.

Yes, I did rotate propshafts back and forth. Seemingly no effect. Obviously a couple rotations by hand may just not paint the whole picture?

Not running drive showers.

Not sure about grease between inner and outer seals? Would one have to pull the seals to check that and then possibly regrease? Could this be the culprit?

No plug on the front of the drive. It is actually a DWP Volvo DPX-R HP duo-prop drive.

Thanks for the help.

Ok.. I am thinking Merc Lower.. They use an internal plug to seperate the water and oil compartments, that can cause a problem. Not sure how Volvo does it.
Again on the B1 lower, there are two grease seals on the propshaft. There is grease packed between the two seals (one faces in, the other faces out). When I pull the bearing carrier, I look at the condition of the grease, that tells me if oil is going out or water is coming in.

Drive shower, if you get enough heat, it can push drive lube out, but not usually allow water in.
So I am at a loss. Although I am not familar with the Volvo. If the water was in there for any length of time, it could cause corrosion. I would feel better if it was opened up and looked at.
Not much help, but some ideas to ponder.

Dick

I had the same problem on a volvo dp290 drive the first year I had the boat there was a little water in when I witerized it so I took it to a volvo specialist and the couldn't find anything wrong but serviced the drive anyways just for cheap insurance 3 years later no problems it was only a few hundred to put new seals in

Thanks for the help Dick. If the grease between the seals is missing would that cause a leak? Not during running because pressure would be up in the drive, correct?

Andyt, thats one of the funny, or not, things. I took it to a, by my knowledge, reputable volvo certified facility after I did my test and explained that there had been water in the drive. They did their own pressure and vacuum tests and came up with nothing and when I asked them to reseal the drive anyway, they told me no, that that would just be wasting money. I told them I would feel better if they did it anyway, but they insisted it was throwing money away, that there was some other explanation for the water getting in, possibly thru the one way seal on the input shaft? I cant see that is possible. There is absolutely no evidence of water being in the bellows. They are completely dry, no condensation, no evidence of rust AT ALL on the u-joints. Go figure?

The grease should show if water was in there, or if drive lube had passed on the way out. But on the dual prop setup, I dont know if they have a double seal. So it may be a mute point.

You are correct, no water in the bellows and it didnt get in there that way.

I would ask the reputable dealer if it fails during the summer, will they warranty it and have it fixed in a day or two?? Or can we just take a look and let me waste my money.. or do you know how the water got in??

They do have a double seal around each shaft. Is it possible to remove and re-install new seals without disassembling the drive? I would think so, right? I am thinking I should do this myself and then go from there. These would seem to be the most likely source of a leak as no other seals recieve the same type of wear.

On the bravo, the bearing carrier needs to be removed, so you pull the propshaft and bearing carrier. Then you have to preload the bearings on reassembly.
On the bravo III there is a seal on each shaft. It looks like one or both could be a double seal. But the bearing carrier is more difficult to get to. Special tools. I have no idea about the Volvo.. Do you have access to a service manual?? That would give you an idea of difficulty. If it is a simple job, go for it. You may be able to find info, online.
I would think that would be a source of a leak. But there are also seals between housings, etc. But they should leak with a psi test. So I would tend to lean toward seals.

you probably have a bad drain/fill seal..