Mounting a ‘spare’ dripless seal to the shaft.

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pcatterall

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We have almost ‘done this topic to death’ now but this is a slightly different slant.
One concern I have concerns the long levity of any of these seals I know that there are reports of seals lasting many years but then I note my TM1 seal is only ‘guarenteed’ for 12 months.
We could be half way through the season in a strange and expensive port and have a sudden problem. Even just craning out and in in our current Marina will cost us 800 euros.
Half way across the atlantic would not be a good place for a seal to fail!
If we had a ‘spare’ seal located on the shaft it would be one less thing to worry about.
I know that I could get the TM sureseal unit which allows a spare to be mounted on the shaft. Possibly a complete TM1 unit could be fastened ( imobilised) to and turning with the shaft? Could you do this with a Volvo seal? Following a failure we would just have to chop off the old unit ( rubber or composite) and slide the new one into place. Perhaps just a couple of gallons into the bilges?
 
pcatterall said:
Could you do this with a Volvo seal? Following a failure we would just have to chop off the old unit ( rubber or composite) and slide the new one into place. Perhaps just a couple of gallons into the bilges?
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The Volvo seal is a very tough lump of hard rubber. It wouldn't be easy to cut up and remove.
 
pvb said:
The Volvo seal is a very tough lump of hard rubber. It wouldn't be easy to cut up and remove.
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Not even with a hacksaw?

I think this is a quite a good idea, especially as on my boat sliding the prop shaft back enough to get one on is a major mission.
 
pcatterall said:
1 1/8th . They fail rarely but lots of potential probs if it goes at a bad time. Why not be prepared?
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If you are that worried about it just switch back to a stuffing box as you can repack that while still in the water. You just have to put up with the drips and grease, both reasons why many people have switched to more modern (and reliable) alternatives.
 
I read of someone who had a length of lorry inner tube jubilee clipped on to the stern tube and held back out of the way. In the event of a failure they could pull it over the old stern gland and clip it on the shaft to keep water out. Obviously they couldn't motor with it like that but they'd be afloat.
 
Pye_End said:
Because I have no idea if you are trying to solve a problem that exists or not.
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Potential problem is that I am relying on a critical component that only has a guarantee of 12 months. Logic suggests that I should change it every 12 months or have a spare ready for rapid deployment without having to lift out, split shaft, drop rudder etc etc.
 
pcatterall said:
Potential problem is that I am relying on a critical component that only has a guarantee of 12 months. Logic suggests that I should change it every 12 months or have a spare ready for rapid deployment without having to lift out, split shaft, drop rudder etc etc.
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My engine's only guaranteed for 12 months, but I have no intention of changing it every 12 months, or of carrying a spare. I don't think your approach is logical; if you feel that the One seal isn't as durable as it should be, why not replace it with something more substantial, rather than buying a second one?
 
Puggy said:
Not even with a hacksaw?

I think this is a quite a good idea, especially as on my boat sliding the prop shaft back enough to get one on is a major mission.
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You would be very fortunate to cut it off without putting a nick or two on the shaft. That's the one (two!) thing that Volvo seals will not tolerate.

What other items are guaranteed for more than 12 months? We are surrounded by consumer items many years old with guarantees of 12 months. Currys send me e-mails on a regular basis asking me to renew guarantees on equipment that has been working well for years. My PSS seal is something like 8 years old, perfectly OK. If it failed I know that a rag and hose clip will almost totally keep water outside the boat.
 
I would be very surprised if it failed after 12 months. All these type seals say you should renew after so many years or hrs motoring. My example of their longevity is as follows(I don't like to admit this on a public forum but it may help reassure you) I fitted a Volvo seal when I re-engined 8 yrs ago, bought off the internet but without any instructions. I fitted it with plenty of the supplied grease and regularly regreased every year. This year it leaked when motoring...... and I decided to replace with a Radice seal which has both a vent and a grease plug. I replaced the seal, had to be lifted out over a weekend, and fitted easily without any problems and no leaks. On examination back home, both internal lip seals had inverted and then I remembered that no fitting sleeve had been supplied when bought and I had just slid it on the shaft. So it had worked without any leaks for 8yrs and about 650hrs, even when fitted incorrectly! And as said a substantial piece of rubber.
 
As I recall people have mixed views on Tides Marine seals (if that is what you mean by TM1), if you are that worried about it then it is not for you. Lashing another to the shaft wouldn't do much for the balance of the prop shaft, possibly speeding up the wear of the seal, gearbox and cutlass bearing.
 
RivalRedwing said:
Lashing another to the shaft wouldn't do much for the balance of the prop shaft, possibly speeding up the wear of the seal, gearbox and cutlass bearing.
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I do agree with you in principle, but my prop shaft is 2 metres long and 42mm diameter and the last time I took it out I could hardly lift the bloody thing and I don't think that a spare volvo seal whirring around on it is going to put it much out of balance.
 
pvb said:
My engine's only guaranteed for 12 months, but I have no intention of changing it every 12 months, or of carrying a spare. I don't think your approach is logical; if you feel that the One seal isn't as durable as it should be, why not replace it with something more substantial, rather than buying a second one?
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Thank you that is very useful
 
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