Volvo shaft seal, serious question

[MissIsle]

I am looking at a Benetau which has a volvo shaft seal in place of a stuffing box. However my mooring is ½ tide & the boat settles down in the sticky stuff twice a day.
Can mud get up into the seal? & could muddy water cause seal wear?
If the seal starts to wear I guess it just drips a bit until you lift out in the winter?
To be honest it looks great, & an incredibly tidy solution, am I looking for problems where there are none?

 

[l'escargot]

Muddy water will cause more wear and you will need to remember to burp the seal every time you use the boat after it has dried out.

 

[MissIsle]

Will the seal actually dry out & need burping every time, since it will settle into the vey liquidy ooze of Fareham Creek?
It's more like soup than mud.

 

[l'escargot]

Are you sure it will remain submerged at all times? I used to keep a boat on a mud berth and sometimes the mud/water would drain away from around the shaft.

 

[Bosun Higgs]

the mud will accelerate wear a bit butthis will apply to any shaft sea and its the stainless that will wear most. the soft always wesars away the hard.
dont worry. its a trivial issue. i have sailed thebristol channel for decades in muddy water and on drying moorings with all sorts of shaft seals. the only one that gave me problems was the deep sea seal

 

[saltylegs]

I agree a wee bit of extra ware may mean a few drips and then replace sooner (maybe) than one thats always afloat but should not be a big deal.

 

[DJE]

They can last a long time. I replaced mine last winter just because I had the shaft out to do the cutless bearing. The old seal had been there for 13 years to my knowledge and I strongly suspect that it was fitted from new 23 years ago! Never a drip!

 

[cmedsailor]

They can last a long time. I replaced mine last winter just because I had the shaft out to do the cutless bearing. The old seal had been there for 13 years to my knowledge and I strongly suspect that it was fitted from new 23 years ago! Never a drip!

Yes, especially when the shaft-engine alignement is good they seem to last for ever.

 

[Tranona]

The main wearing part in the seal is actually the fluted rubber bearing which is similar to a cutless, rather than the seals themselves. There are also two seals and the second one never gets near water unless the first one fails. some Beneteaus have an air vent so you may not even need to burp the seal as water fills the tube automatically.

 

[cmedsailor]

some Beneteaus have an air vent so you may not even need to burp the seal as water fills the tube automatically.

Not really air vent, it's a little hose from the hull bottom towards the beginning (or end depending how you see it) of the shaft tube just before the volvo seal.
Yes, it's purpose is to lubricate with sea water the volvo seal but I think it does not completely fill the tube automatically. From my experience I forgot once to remove the air as soon as the boat was back in the water, did it after using the boat for some hours and there was still air traped in there. Have no idea if eventually the air would have burped itself.