Oil filled stern gland. Help needed to identify and work out a fix

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djs

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www.uniquesolutions.co.uk
I’m posting this on behalf of a friend, Holly, an American single hander, who like us is stuck here in Panama with all destinations to the west closed.

she has a gradually worsening leak from the stern gland.

hopefully I’ve been able to attach some photos.
We would like to identify the type and also work out what might be the cause of the leak, whether it’s likely to get worse, what are the chances of a sudden failure and how to fix it - if it’s possible. Haul out at the moment isn’t possible.

the small tube to the top of the seal comes from a small oil reservoir. If the reservoir is topped up the oil level drops away completely over the course of about 12 hours.

the boast is a1982 Grinde. 1 Inch propshaft.

any help or leads to tech info on the would be appreciated. We’ve looked at Vyv’s website and that helps us understand that it’s probably a number of lip or oil seals in the body of the gland. We are after more specifics to help us work out how serious this is andwhat we may be able to do with the boat in the water.

thanks. Right now how do I attach these photos...E01C545B-D990-4443-B7BA-2D7F0CAB3CAE.jpeg9C80E42B-5058-4407-A56E-B68106D1F6CA.jpeg67159688-2B42-4E88-B9FC-5E40D55D5339.jpegEB46F570-7835-488F-A62E-66ECCFB8C1D8.jpeg
 
The arrangement is similar but not absolutely identical to my stern gland on a Bukh.

On mine there are two lip seals between the oil entry hole in the gland and the sea. That is, towards the propellor. If it's leaking oil by that route they are clearly failing. They are underneath where the shaft hose is clamped onto the gland. To replace them you have to remove the gland from the propshaft.

There's a third seal in the gland at the end near the gearbox. This could leak on its own, but in that case the oil would end up in the boat rather than leaking into the sea. Again the gland has to be removed in order to replace that seal.

But from the description and pics it seems likely that the outer seals, towards the prop, are failing.

I had a similar failure on passage once. The sea got into the bearing and then into the oil pipe and reservoir. I rang the supplier of the gland who said I could continue to operate effectively under water lubrication providing the gland, which was bronze, was kept cool. Apparently basic metallurgy meant it wouldn't seize on the stainless propshaft.

And providing I had a serviceable bilge pump, I needn't worry too much about leaking through the inboard gland if that also began to fail. The gland was a relatively close fit on the propshaft and wouldn't let water in at an unmanageable rate.

I continued the passage. But lifted out on arrival a couple of days later.
 
As far as fixing it is concerned, I needed to take off the flange at the gearbox end of the propshaft, loosen the clamp on the hose and slide the stern gland up over the end of the propshaft. This is the point where the ocean would rush in and I wouldn't want to try this afloat.

Getting the flange off can be difficult. And the propshaft needs to move aft as it is drawn out of the flange. And further aft to get the gland off it. On my boat I have a shaft anode to take off to allow this movement.

Replacing the seals is easy enough, once you have them. But you could replace the whole unit with a different system if that were easier. I've always been happy with mine, but keep spare seals to hand, and replace as soon as any significant oil loss begins.
 
The arrangement is similar but not absolutely identical to my stern gland on a Bukh.

ah. Holly’s engine is also a buhk.

thank you for the description of the construction and experience with one failing. We’ll chat with Holly about how we may be able to reduce the leak.

If it's a Grinde it has to be Wind Hippie Holly, she has a great Youtube channel, a real proper sailor she is...:)

indeed it is, and I agree about her capabilities. She’s been a great person to share anchorages with.

thanks all.
Dave

if holly has any further questions after seeing this she’ll post them here.
 
I concur, the red paint on the gearbox screams Bukh too. It is like the seal on our Bukh DV 20, but we have no flexible hose as the prop shaft is split and uses a U/J behind a thrust bearing. Our seal is integral with the stern tube.

I think a short term method might be to use a far thicker oil, perhaps even a light grease.

Feeding with a sealant gun via an empty cartridge?

Very careful not to overpressurise and push out the seals!

My two pennyworth anyway.
 
Substituting grease was my thought also. Should prove very effective when the shaft is stationary, not too sure if rotating but should get the boat to where it can be lifted out. Fortunately the seals are cheap and readily available almost everywhere.
 
Hi it’s Holly here. Thank you guys so much for all the helpful comments. Substituting grease is a great idea; I’ll see if I can do that to at least mitigate the leak while I’m not motoring. I don’t usually use my engine anyway, so grease could be a great solution. I probably won’t have a chance to haul out until October, so I’m hoping I can keep the leak from getting worse until then. Do you guys know what the worst case scenario if I get a total seal failure? I have limited bilge pump action
 
Worst case..
With a big pump handy, we pulled the packing out of a conventional seal, expecting a rush to get the new bits of 'rope' back in. Actually there was very little seepage, as the bronze was a close fit on the shaft. That seal had a grease feed from a little reservoir that one gave a turn every so often.
Nightmare scenario would be the seal getting hot and seizing on the shaft and twisting off the rubber tube, but I very much doubt that, as if there is any lube about it will keep turning.
 
My experience was that water got into the gland which heated up and blew the oil out of its reservoir. I didn't have a functioning cap on it at the time. So when I needed to run the engine I kept the gland cooler by spraying water on it from time to time. Obviously this, plus the leakage, had to be pumped out, easily done with a manual bilge pump.

With the engine off I still had a water leak from the gland, no more than a couple of drips a second or so as I recall. Not a problem at that rate.

If you can keep pouring oil into it maybe it won't get much worse? I like the ideas of putting thicker oil in it, my Bukh owners manual says use outboard gear oil, or EP90 I was told.
 
If you do try it In the water then having a replacement assembly would be a good idea along with all the people you can get on the foredeck
Try Albin in Denmark but first check it’s not 25mm
 
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