Oil bath type stern gland

CliveG

CliveG

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Hi

Can anyone recognise this stern gland?
Shaftseal.jpg

It has an oil bath between 2 seals and has a tube ranning to a plastic header bottle fitted high up in the cockpit locker.
It is fitted to my Evolution 25 and as far as I know has been since she was built.
There has been a random leak every now and then when under power and it can only be coming from this gland.

I have had it out this winter and have cleaned it and the bottle.

I am now wondering what Oil I need to refill it with.

Has anybody any idea?
 
No, but I know a man who can:

vyv_cox is your man. Hopefully he will reply to your thread, but in the meantime his website is here:

www.coxengineering.co.uk

There are plenty of photographic stern gland examples on his site. Hope this is of some help for the moment.

Best of luck
 
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Thanks for that.
A useful site but my seal is not there.

Just a note.
That photo was from when I brought the Evo.
The rubber stern tube was replaced prior to her 1st launching.
 
Mine had what looked like the letters BMW on the casting, but I couldn't be sure as the casting was quite rough. It looks a bit like a B on yours near the oil feed pipe, but hard to tell from the photo. I wondered if it was a seal BMW knocked up to compliment the infernal D7 engine.

I tried all sorts of oil in mine and discovered only one thing. That they all made a mess once deposited in the engine bilge. There were bottles of ATF and outboard leg oil on the boat when I got it, so wonder if one of these was what the previous owners had used.

I tried to identify mine without success in order to allow me to obtain new lip seals whilst it was still fitted, but failed to do so. As it would have meant having the boat lifted to remove the seal and take it away to size up, obtain and fit new lip seals, I didn't bother and fitted a new PSS instead as it was cheaper than the lifts.

When I did remove the seal, I found that the inside of the casting had been damaged by the propshaft running against it at some point and was badly worn. This meant that one of the lip seals was not properly supported in its slot, and the thing was a write off anyway. So, deciding to replace it was a good call on that count too.

From experience, my advice would be if you can get the boat out of the water at no cost, take the whole thing to a good seal place and have them put new lip seals in it. If getting the boat ashore will cost you, spend the money on a new seal instead.

Incidentally, that rubber hose looks way past its best too. I'd not sleep well until I'd changed that!
 
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At least a similar principle to Halyard

beserksail said:
Looks similar to a Halyard seal.
Click to expand...
However they stopped making them. I tried to refurbish one but with no success. The lip seals have to be glued in place and oven backed and god knows what else. I truly liked them a lot but they are no more (correct me if I am wrong).
I am changing to PSS as well. Its a much too important piece of gear to mess around with yourself.
 
Fairey used a similar system; their stern glands had a bronze journal lubricated with grease which was retained by lipseals either end and the whole thing had a waterjacket to keep it cool fed from the engine's SW outlet.
 
I've supplied modern lip seal systems (oil filled) we had our own grade of oil that was biodegradeable in case of leaks. There will be two lip seals as others have said these should be easy to replace, tapped in with a socket that sits on the hard metal part of the seal. Shafts can get worn by the seal over time so check for ridges in the shaft. The lip seals should be standard sizes and the same as automotive seals.

Make sure you put them the right way round, one stops water coming in the other stops oil getting out.

The system we supplied and I serviced used synthetic gear oil 75w - 90.
 
CliveG said:
Thanks for that.
A useful site but my seal is not there.

Just a note.
That photo was from when I brought the Evo.
The rubber stern tube was replaced prior to her 1st launching.
Click to expand...

Your exact seal is not shown but the ones by Bukh and Vetus are of the same design, as are the Halyard ones mentioned by other posters.

Engine oil or ATF should be perfectly OK but Neil Y's suggestion seems like a good one.
 
Same as Vega

Hi. This gland is very similar to the ones provided originally to the Vega. They have two white metal bearings inside and a lipseal at each end. Ive never had to glue any seals in and found them to be low-maintenance and long lasting.

They were originally grease filled but the change to a tick oil with a slight amount of positive pressure was/is a well known modification.

The Vegas have had these for over 40 years and there were 3450 Vegas made between 1968 - 1978

Cheers Steve Birch
 
Thanks to all for the help.
I think the lip seals are o.k.
No water would come in whilst on the mooring or when motoring on the level.
It only seems to come on when motor sailing and then not always.
I had not understood the need to keep the oil topped up.
We are ashore at the moment and I have had the seal of the shaft and cleaned it all out of gunk.
I just wanted a guide on the type of oil to refill with.
Looks like a gear oil may be the way.

As I said above I replaced the reinforced rubber tube at the recommendation of the purchase survey prior to her 1st launch.


Thanks again.
 
CliveG said:
As I said above I replaced the reinforced rubber tube at the recommendation of the purchase survey prior to her 1st launch.
Click to expand...

Somehow I completely missed your second post in which you mention the hose having been replaced.

One possibly nowadays irrelevant warning about the use of gear oil. The EP additives used in such oils were said not to agree with phosphor bronze bearings, which is essentially what the inside of the seal is. I'm told by many that this is unlikely to be an issue with current EP oils, but cannot find definitive confirmation of the fact. Ultimately, the bearing function of the inside of the seal is crude, far from a close tolerance precision fit and subjected to virtually no load, as would be the case in a gearbox application where such bearings and oils might find themselves in less harmonious company. So, it's probably not worth worrying about too much, but something to bear in mind if it is possible to pick between oils with and without EP additives.
 
Embarrassing?

ashonavega said:
This shows the seal which used to be fitted to my Vega. I used 2 stroke oil in mine. The aft seal started to fail in mine so that it would dump the oil. A bit embarrassing in a marina.

3OldViewbeneathCockpit.jpg


Ash
Click to expand...
Would cost you 5000 USD per incident in the US. Unless you are Deep Water Horizon though, they got a quantity discount.
 
There should be 3 seals in the unit.
Starting from the prop end the seals should be fitted ] [ ] that is the rear most seal lip out (seaside) next seal lip forwards (oil side) and the final seal (foremost seal) lip rearwards (oil side). The 2nd and 3rd seals retain the oil while the first (propside seal) stops the water / dirt coming and protects seal #2.

Seals do not need baking or any other fancy treatment and are standard sizes eg 25/35 Niton with SS spring - make sure you specify a niton seal with SS spring
 
I don't understand the recommendations for gear oil. EP additives are for steel-on-steel situations, totally different from this duty. In similar applications in pumping the oil used is low viscosity hydraulic oil. Can anyone explain why a heavy gear oil with high additive content is required?
 
Vyv,

I believe it's the need for high viscosity which leads to the suggested use of gear oils. The thicker the oil, the less likely it is to leak out. Simple as that. The additives are irrelevant, but just happen to come in those oils.

The thick oil may also be intended to help prevent the oil so readily accepting any water which makes it past the outboard seal into emulsion, thus preventing a worsening cycle of progressively thinning oil in the seal and more rapidly increasing water content as the oil becomes a less and less effective barrier. Apparently it's quite common for these seals to 'make oil' at a not inconsiderable rate once this begins to happen, which makes a real mess when the reservoir overflows.
 
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Simondjuk said:
Vyv,

I believe it's the need for high viscosity which leads to the suggested use of gear oils. The thicker the oil, the less likely it is to leak out. Simple as that. The additives are irrelevant, but just happen to come in those oils.

The thick oil may also be intended to help prevent the oil so readily accepting any water which makes it past the outboard seal into emulsion, thus preventing a worsening cycle of progressively thinning oil in the seal and more rapidly increasing water content as the oil becomes a less and less effective barrier. Apparently it's quite common for these seals to 'make oil' at a not inconsiderable rate once this begins to happen, which makes a real mess when the reservoir overflows.
Click to expand...

Higher viscosity isn't really going to help TBH, if the seal's knackered it's knackered. As you point out if there is a loss of sealing the leak is usually inwards(important for pollution control) if the system is properly designed, the reservoir should also have enough ullage to accommodate the oil contained in the system below the waterline. If not, or if overfilled, you will get both the overflow you describe and possible leakage of oil into the sea.
 
Just for the record we can supply bearings for these made from composite, to replace the white metal. The lip seals do need a close tolerance bearing so the seals aren't loaded as the shaft tries to flex, this could be why you would see leaks motoring as the engine will try to move on its mounts just from going up and down waves.
 
penfold said:
Higher viscosity isn't really going to help TBH, if the seal's knackered it's knackered. As you point out if there is a loss of sealing the leak is usually inwards(important for pollution control) if the system is properly designed, the reservoir should also have enough ullage to accommodate the oil contained in the system below the waterline. If not, or if overfilled, you will get both the overflow you describe and possible leakage of oil into the sea.
Click to expand...

I wasn't intending to suggest that thick oil would stay in if the seals were shot. Simply that it will leak less rapidly if the seals are not absolutely perfect. As anyone who has ever out a low viscosity modern synthetic oil into a tired old car engine will know, it will find and escape from anywhere there is even a slight weakness in the oil seals.
 
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