Which replacement shaft seal?

ive nothing against the Volvo seal, just keep the boat on a drying mooring and its a pain in the a*** to get everything out of the locker everytime to burp the think, so iv anyone is looking for a Volvo seal i will have one for sale this winter
 
vyv_cox said:
I think you will find that is standard advice, nothing to do with the seal type. There are three components that can be flexible in any installation - engine mountings, coupling and seal mounting. However, if all three are flexible the installation will be uncontrollable. The rule of thumb is that any two can be flexible but one must be fixed.
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Slightly confused by the phrase "nothing to do with the seal TYPE" while agreeing your overall summation. Perhaps "nothing to do with the MAKE of seal"
It does mean any flexible seal, not just VP's own.
The VP manual says if you have flexible engine mounts and a flexible shaft seal you must not have a flexible coupling. It's illustrated with drawings of a VP seal and another incorporating a bellows.
It then says, if you have flexible mounts and a rigid shaft seal, you must have a flexible coupling.
 
bert49uk said:
ive nothing against the Volvo seal, just keep the boat on a drying mooring and its a pain in the a*** to get everything out of the locker everytime to burp the think, so iv anyone is looking for a Volvo seal i will have one for sale this winter
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I too dry out but luckily can reach the seal through the engine hatch so it's easy.
My previous boat had a vent pipe glassed into the stern tube just behind the seal and going up high above water line so the seal became self burping.
When my VP seal needs replacing I will get the Radice - have you seen it - direct replacement for the VP (and a bit cheaper) but with a built in connector for a vent pipe to be self burping, that would solve your problem.
Second item on this page http://www.sillette.co.uk/documents/IWMVersionTidesMarineElicheRadice-17.9.11.pdf
 
Troubadour said:
I too dry out but luckily can reach the seal through the engine hatch so it's easy.
My previous boat had a vent pipe glassed into the stern tube just behind the seal and going up high above water line so the seal became self burping.
When my VP seal needs replacing I will get the Radice - have you seen it - direct replacement for the VP (and a bit cheaper) but with a built in connector for a vent pipe to be self burping, that would solve your problem.
Second item on this page http://www.sillette.co.uk/documents/IWMVersionTidesMarineElicheRadice-17.9.11.pdf
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Aa i posted earlier i have a PSS ready to go on
 
Hello again

First of all thanks to all the forumites that have responded and for the information, thoughts and comments – marvellous! Within just seven minutes of posting I had the part-number for the Volvo 1” shaft seal which, up to that point, I wasn’t sure existed. (Thanks, Awol.)

A late night lat night gave me a bit of time to review the info and investigate a little further. Here’s the update.

I’m replacing a relatively complex Halyard HMI seal, an oil lubricated type, and so find myself favouring the simpler solutions – I’m attracted to reliability, ease-of-use and ease-of-replacement. Consequently I have discounted those seals that require oil or pressurised water lubrication. (My seawater pump impellers seem to fail, on average, about once every 0.8 seasons so the risk of consequential damage to a pressurised-water lubricated shaft seal seems unacceptably high to me. Perhaps I’m over-reacting.)

That appears to leave me with the Volvo, Radice, and PSS seals (the latter despite the current controversy). I’m not happy using a 25mm seal on a 1” shaft so that discounts the Radice as it only comes in metric sizes (pity). I really like the Volvo concept but my stern tube (diameter yet to be checked/discovered – it’s a Marine Projects built boat from the late eighties so probably the same tube as in Moodies of that period) has a significant lip on the end of it. Both the Volvo and the PSS seem to require a smooth stern tube so neither may yet prove suitable without serious surgery to the tube itself - something I'd prefer to avoid (space, time, cash). Also the PSS seal seems to be quite large and I'll need to check the height of the shaft from the hull where it exits the stern tube.

Incidentally, regarding the “flexible-coupling” debate, I have an RandD flexible coupling in my drive shaft but could, and would, consider reverting to a rigid coupling. I’m not a trained engineer and bow to the greater knowledge of those that are but is it possible that the manufacturers advice regarding incompatibility of flexible shaft seals and flexible coupling might be about the increased fore-and-aft compliance such a coupling allows increasing the wear rate on the critical lip seals? I know it knackers them on a Baby Blake!

Please note, I'm away for the next couple of weeks so further updates unlikely until my return. Thanks again for all the info so far. If anyone knows about the stern tube size (no time to get back to the boat) please add it to the thread.
 
Troubadour said:
This idea comes from Volvo Penta actually.
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Its advice that seems to be widely ignored by Volvo's OE customers.

It is rare to find an installation now that does not have a flexible coupling, and even more rare to find one that has a shaft with a bearing at both ends of the stern tube. I suppose than constant sideways movement could damage the mounting, but Volvo also recommend a service life of 5 years, which many people will confirm is very conservative. Suspect the advice is given in the same way as the 7 year life on saildrive diaghrams!
 
Tranona said:
Its advice that seems to be widely ignored by Volvo's OE customers.

It is rare to find an installation now that does not have a flexible coupling, and even more rare to find one that has a shaft with a bearing at both ends of the stern tube. I suppose than constant sideways movement could damage the mounting, but Volvo also recommend a service life of 5 years, which many people will confirm is very conservative. Suspect the advice is given in the same way as the 7 year life on saildrive diaghrams!
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I'd have to disagree with that. My 1985 Beneteau had a VP2002 with a solid coupling and a VP shaft seal; my 2003 Jeanneau has a VP2020 with a solid coupling and a VP shaft seal. I've no reason to think mine are different from thousands of others. Rigid couplings are the standard VP offering - have a look on marinepartseurope.com

Note Vyv Cox's comments too. The problem is too many degrees of freedom and potential oscillation.

Happy to agree with you about the 5 year life. A friend of mine has a 1990 Feeling with a Yanmar engine and VP seal (oh, and a solid shaft coupling) and he's still on the original seal. Not sure I'd push it that far personally!
 
Please excuse me for re-opening this ageing thread but I thought I ought to let you know of the final decision.

Eventually I went for the PSS seal. The thing that swung it was the availability of imperial sized units plus the 1.875" lip at the end of my 1.75" stern-tube. I sought advice/info from several sources and decided that the V-P unit was unlikely to stretch over the lip, whereas I was advised the PSS would. Indeed the manufacturer's web-site (but not the UK supplier's) says the unit I've bought would suit a 1.875" stern-tube anyway.

So there we are. I'll only post again on this thread if I have a problem with the thing!

Thanks for all the help.
 
I must have missed this thread the first time round, probably when I was away sailing. Like the OP I have a Sigma 362, I bought her three years ago, already fitted with a PSS seal. It has been very satisfactory so far-except the first year. What seemed to have happened is that I got eel grass up the stern tube, presumably reversing out of the marina berth. Bits of eel grass got in between the faces of the seal allowing the ingreess of water. At the time I tried squeezing the faces together (engine stopped obviously:eek:) to cure it but I think a better option is to push the bellows back to try and flush out the offending material, if you see what I mean. When leaving the boat I check the stern gland is not leaking, I'm in under the stern cabin berth anyway turning off the seacocks and also leave the gear lever in gear and astern, then the shaft shouldn't turn and all 'should' be ok. Has been so far.

On my list of jobs for the winter is to replace the bellows, haven't started investigating that one at all yet.
 
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