Volvo Shaft Seal - Life span

[Chris_Robb]

I Tried to do a search on this, but no luck - sure its been discussed before.

The Manual says change every 500 hours. I have done 500 hours this year alone - greased every 100 hours. Since I have had the boat it has done 1000 hours. I don't know how old it is, but the previous owner left all the servicing to Volspec so they probably had changed it at some point.

Its not showing any sings of dripping or wear, It runs just warm to touch, and seems to need burping on a regular basis as air always comes out from it.

Any one got some practical advice on this. Perhaps I should just change it, but I am loath to do work which might just create a problem (DIY = dmamge it you self!)

 

[Heckler]

I Tried to do a search on this, but no luck - sure its been discussed before.

The Manual says change every 500 hours. I have done 500 hours this year alone - greased every 100 hours. Since I have had the boat it has done 1000 hours. I don't know how old it is, but the previous owner left all the servicing to Volspec so they probably had changed it at some point.

Its not showing any sings of dripping or wear, It runs just warm to touch, and seems to need burping on a regular basis as air always comes out from it.

Any one got some practical advice on this. Perhaps I should just change it, but I am loath to do work which might just create a problem (DIY = dmamge it you self!)

Ive always been under the impression that they should be changed every 5 years, advice from a well respected Beneteau man. I know that when they wear they start to drip at first, so you do get a hint that they are on the way out. They dont fail catastrophically, on Beneteaus they have a separate raw water feed in to the back end of them, is yours a Bene? You only need to burp when the boat has been out of the water, perhaps you are overdoing it? Greasing with the blue grease is recommended to be done yearly. We are talking about the Volvo "bullet" ?
Stu

 

[Chris_Robb]

Ive always been under the impression that they should be changed every 5 years, advice from a well respected Beneteau man. I know that when they wear they start to drip at first, so you do get a hint that they are on the way out. They dont fail catastrophically, on Beneteaus they have a separate raw water feed in to the back end of them, is yours a Bene? You only need to burp when the boat has been out of the water, perhaps you are overdoing it? Greasing with the blue grease is recommended to be done yearly. We are talking about the Volvo "bullet" ?
Stu

Stu - yes this is the Volvo one.

On a Westerly Ocean lord. Always burp on Launching - always grease as well once a year - but 4 times this year! Just noticed this year that air can be burped out on a regular basis, and I was just wondering if this was normal.

Perhaps I should have a spare on board as we are in Greece and it would be difficult to get a replacement at short notice.

 

[Kwik Decision]

Our boat came with one of these stern glands, which the PO had fitted in 2002. The instructions (which were in the comprehensive file of paperwork he handed over with the boat) stated that it should be changed every 7 yrs / 700 hrs. I changed it in 2009, and noted that the instructions with the new one said it should be changed every 5 yrs / 500 hrs.

Now either Volvo have noted that there is a risk that they wear out faster than they originally thought, OR they are not selling enough. You pays your money and makes your choice.....

 

[Chris_Robb]

Our boat came with one of these stern glands, which the PO had fitted in 2002. The instructions (which were in the comprehensive file of paperwork he handed over with the boat) stated that it should be changed every 7 yrs / 700 hrs. I changed it in 2009, and noted that the instructions with the new one said it should be changed every 5 yrs / 500 hrs.

Now either Volvo have noted that there is a risk that they wear out faster than they originally thought, OR they are not selling enough. You pays your money and makes your choice.....

At least that means that my seal is at least not as old as the 7 year 700 hours instructions!

 

[pvb]

As with "Use by" dates on food, Volvo's replacement recommendation is very conservative. I'd keep using it until it starts dribbling water, then replace it.

 

[Heckler]

Stu - yes this is the Volvo one.

On a Westerly Ocean lord. Always burp on Launching - always grease as well once a year - but 4 times this year! Just noticed this year that air can be burped out on a regular basis, and I was just wondering if this was normal.

Perhaps I should have a spare on board as we are in Greece and it would be difficult to get a replacement at short notice.

Ive changed a couple of them, easy enough to do, possible in the water even with a couple of tea towels and plenty of access, undo the flange to the gear box, work out what holds the flange on, tapered shaft and key with a big nut or a split flange. Get the flange off, you may need a big puller. Make sure the shaft is free of burs, grease the new bullet and fit the split red plastic protector in it. Undo the 6 mm nuts and bolts on the bullet clamp, get SWMBO ready with the tea towels to stem the flow of water, whip off the old bullet and slide on the new. Panic over and redo everything. About £70 ish from Volspec for a 25mm one.
I would look at the shaft spinning under way to see if all is lined up first and check, if you have a water pipe to the gland, that all is clear of obstructions first.
Stu

 

[Chris_Robb]

Ive changed a couple of them, easy enough to do, possible in the water even with a couple of tea towels and plenty of access, undo the flange to the gear box, work out what holds the flange on, tapered shaft and key with a big nut or a split flange. Get the flange off, you may need a big puller. Make sure the shaft is free of burs, grease the new bullet and fit the split red plastic protector in it. Undo the 6 mm nuts and bolts on the bullet clamp, get SWMBO ready with the tea towels to stem the flow of water, whip off the old bullet and slide on the new. Panic over and redo everything. About £70 ish from Volspec for a 25mm one.
I would look at the shaft spinning under way to see if all is lined up first and check, if you have a water pipe to the gland, that all is clear of obstructions first.
Stu

Thanks for that Stu. No waterpipe to gland, and shafts runs with no vibration so alignment I hope is good. I was looking at the coupling, and it looks like a split coupling with alan screws holding it together with a big bolt straight through the unit as the locator, so should be easy to take off........ ie no taper to break.

 

[Red Admiral]

No real position to offer advice but I bought a new shaft gland 10 years ago when I bought my boat and it's still in its box! Patiently waiting for the existing gland to start dripping suggests that it will outlast me. I just make sure it gets plenty of grease whenever boat is out of water.

 

[nedmin]

My previous twin engined boat was 10yrs old when I sold and still on original seals, This one done 8yrs and still OK. This is on the Humber, Yorkshire Ouse and Trent, all very silted rivers especially the tidal Ouse.I,m very impressed!They wont fail dramatically,will just start dripping first.The advantage of this seal is that its got its own cutless bearing,so whatever the shaft moves,ie up and down,the seal follows it.

 

[philip_stevens]

I replaced the originally fitted Volvo shaft seal last year, on our 1986 Duo. It had never been changed by previous owners, and was not dripping. We have had her for 5 years.

The only reason it was changed was that the engine had to come out for refurbishment, and the coupling was taken off (and a sod to get off at that) to allow the shaft to be retracted.

 

[Jonathanpaul]

Hi,

I don't think holding a spare unless it leaking is a good idea. The rubber goes hard over time. That's what I was told by suppliers. I also had one on my Beneteau for years. Its started to drip only when underway. I repalced it thi year and the new one has no leaking at all. Great bit's of kit.

 

[bobm]

Ours has just started to leak, boat 10 years old, 800 engine hours, regular service, greased annualy, burped each time boat is out of water. Will leave until winter lift out, did not seem to drip at all until this year then suddenly started, not overly concerned at the moment.

 

[Martin_J]

Chris -... not sure if you're in Haslemere. If you're in Southsea any time you could check out the one I removed from a previous boat so you can see the real thickness.

What was surprising was that although mine looked perfectly sound after about seven years use.... there was quite a deep crack around about a third of the circumference... just forward of where the jubilee clips were.... The crack was just visible when trying to flex the seal by hand in every direction.. but once removed was very very visible.

Maybe not so easy to describe.. I'll take a picture later.. Very difficult to find the split as well when installed but once I knew it was there it was so obvious.


I also then changed it 'in the water'...

 

[Chris_Robb]

Chris -... not sure if you're in Haslemere. If you're in Southsea any time you could check out the one I removed from a previous boat so you can see the real thickness.

What was surprising was that although mine looked perfectly sound after about seven years use.... there was quite a deep crack around about a third of the circumference... just forward of where the jubilee clips were.... The crack was just visible when trying to flex the seal by hand in every direction.. but once removed was very very visible.

Maybe not so easy to describe.. I'll take a picture later.. Very difficult to find the split as well when installed but once I knew it was there it was so obvious.


I also then changed it 'in the water'...

Back in Haslemere for a couple of weeks dodging the heat. I will give you a call.

Thanks all for your answers.

 

[Martin_J]

Found it... I have the original stern seal.. complete with 'not so easy to find' split.....

Looking at it again, a couple of years later... it's the sort of split that you would not see on first inspection...