DPH water ingress

[spray]

DPH-c Volvo serviced 9 months ago and since approximately 30 hours use. Now, my own oil change found the oil milky, obviously contaminated by water (sea). A subsequent pressure test revealed a very small leak on the prop shaft seal but the leak results were within Volvo limits. No obvious reasons of damage such as fishing line. Is it worth paying ££ for new seals or continue to use for another 30 hours before changing the oil again ? I see there have been reports of leaks before and mine is not an isolated case, your thoughts would be appreciated.

 

[gjgm]

I would have thought the last thing anyone wants inside their outdrive is seawater.
By all means be absolutely sure it is thru that seal, but get it fixed ,whatever it is !

 

[spannerman]

When I service Volvo drives if it is a twin installation there was nearly always water in one of the drives. Volvo have a crap system for protecting the prop seals unlike Mercruiser which have a metal shield as part of the seal. The problem is that with water in the oil the small pinion gear which transmits all the horsepower to the two large gears in the lower section is the most heavily loaded gear and with water in the oil the lube film breaks down resulting in pitting and chipping which then means the whole gear set has to be replaced as they are a matched set and that makes prop seal replacement seem like peanuts. I always inspect this gear when I find water in the drive, as if its caught early you can be lucky but continued use increases the risk of failure.

 

[spray]

Thank you for your replies. The only detectable leak was at the bottom of the larger shaft seal. I will have this repaired and hopefully all will be good. Strange that the pressure test leakage was a pass in Volvo’s spec. A vacuum test was mentioned but apparently the leg has to be removed, hopefully this won’t be needed.

 

[spannerman]

I don’t know how many hours your drives have done, but in the literally hundreds of Volvo prop shaft seals I have replaced in the last 30 yrs I have often found that the shaft gets a wear groove from the seal with higher hours. Its possible to reposition the new seal a couple of millimeters one way or the other so the seal lips ride on a flat part of the shaft which buys you more time wirh the drive.

 

[spray]

I don’t know how many hours your drives have done, but in the literally hundreds of Volvo prop shaft seals I have replaced in the last 30 yrs I have often found that the shaft gets a wear groove from the seal with higher hours. Its possible to reposition the new seal a couple of millimeters one way or the other so the seal lips ride on a flat part of the shaft which buys you more time wirh the drive.

Thank you for your advice, I will certainly ask the Volvo tech to do that. The engine , 2014, has run 260 hours.

 

[spray]

Spannerman, one question please, the filler plug had the pressure test equipment installed there so the plug could also be at fault, would a sealant around this be advisable in case of it not seating correctly?

 

[spannerman]

I guess they used a standard filler plug with a hole drilled and tapped to take a pressure coupling. Thats what we use, there should be the normal green O ring on the filler plug and a gasket or O ring on the fitting which screws into the filler plug. If it doesn’t hokd the pressure then I spray soapy water around the prop shaft seals AND tge gearshift quadrant as these leak also, and around the pressure fitting to identify where its leaking. A vaccuum test should be done also as a drive gets warm when driven and when it cools down it can suck water in past seals.

 

[madabouttheboat]

DPH-c Volvo serviced 9 months ago and since approximately 30 hours use. Now, my own oil change found the oil milky, obviously contaminated by water (sea). A subsequent pressure test revealed a very small leak on the prop shaft seal but the leak results were within Volvo limits. No obvious reasons of damage such as fishing line. Is it worth paying ££ for new seals or continue to use for another 30 hours before changing the oil again ? I see there have been reports of leaks before and mine is not an isolated case, your thoughts would be appreciated.

Should vacuum test it too. In my experience, DPH drives leak from the gearshift linkage as often as they do from shaft seals.

 

[spray]

Thanks for your replies, very helpful to know. Volvo told me the the leg needs removal for a vacuum test, presumably to check the seal inside the upper below.