Leaking volvo stern gland: How worried should I be?

laika said:
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OK, that's an R&D coupling. You'll need to loosen the nuts which clamp the propshaft. You may need to twist a screwdriver in the slots to "encourage" the clamping surfaces to release slightly. There should be a key in the shaft, which you'll need to remove to slide a new seal over the shaft.

The new seal will come with a plastic insert, to protect the lip seals whilst the seal is slid over the shaft.
 
I had a leaking Volvo seal after it was installed by a 'professional' who didn't bother with the applicator sleeve so that one part of the outer lip folded under itself. Rather than leave it drip I simply tightened a hose clip sufficiently when leaving the boat to stop the drip and loosened it when back aboard. This nursed it through several months until the usual haul-out time.
 
My coupling was made on the same principle as that one, though it looked a bit different. Changing a shaft seal is a job to do on the hard, not in the water unless you are prepared to get a lot of water in the bilge and have someone to hold the shaft so that you cannot lose the end of it into the stern tube. On some boats (and mine was one) it was short enough to be taken right out without the propeller even touching the rudder.

When you remove the nuts on the coupling you will find that you also have to slacken the bolts. Even then you might not be able to pull the shaft out. Be prepared. Get two strips of hard steel just thin enough to put into the slots. Gauge plate is the type of steel you want, its high carbon steel and a lot harder than ordinary mild steel which might distort and jam in the slots. Take out the bolts and put them back in the other way round so that tightening them against the hard steel strips very slightly springs the slot a little wider. The shaft should come out fairly easily now. Be careful not to lose the key if your particular coupling has one. Mine did and I would be a little wary of one that just relied on clamping pressure alone.

When you do this job its a good time to check and if necessary renew the cutless bearing whilst the shaft is out.

EDIT: The trick with a screwdriver in the slots might work for you, but my coupling (a different make) required the treatment I described.
 
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Norman_E said:
When you remove the nuts on the coupling you will find that you also have to slaken the bolts. Even then you might not be able to pull the shaft out. Be prepared. Get two strips of hard steel just thin enough to put into the slots. Gauge plate is the type of steel you want, its high carbon steel and a lot harder than odinary mild steel which might distort and jam in the slots. Take out the bolts and put them back in the other way round so that tightening them against the hard steel strips very slightly springs the slot a little wider. The shaft should come out fairly easily now. Be careful not to lose the key if your particular coupling has one. Mine did and I would be a little wary of one that just relied on clamping pressure alone.
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That procedure won't work with the OP's R&D coupling. It works with some Volvo Penta couplings, in which the holes are threaded, and the bolts don't have nuts.
 
My boat has a shaft held in place with a large nut inside the coupling flanges. Easiest method is to undo the bolts, slide the shaft out slightly, undo the nut and simply remove the end fitting. Of course it isn't quite that simple and it won't budge. :D

I replace the original bolts with longer ones, put a piece of metal rod on the end of the shaft and tighten up to force the shaft out of the fitting. Some heat is also usually required.

OPs version looks as if it will be easier to remove. The trick with longer bolts might still help if there's a hole inside the flange.
 
Bobc said:
It won't just let go on you, it'll just keep dripping more and more as time goes on.

If you get some thick silicone grease and push it into the seal (with a McDonalds straw works well), then that will give it a bit more life.

They are easy to change, but replace it with the Radice version, as it has a grease point and also a breather, so you don't have to burp the air out of it when it goes in the water (they're a bit cheaper too).
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McDonald’s straw was great two or 3 years ago but they are paper now and are likely to cause more problems by tearing
 
An alternative to the straw is a small plastic syringe obtainable from a chemist 5ml size can fit easily between the lips without damage. The secret to fill it with grease, is to warm the grease first before you "suck" to charge the syringe.
 
Homer J said:
McDonald’s straw was great two or 3 years ago but they are paper now and are likely to cause more problems by tearing
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I saw that coming and laid in a stock of plastic straws. A bit overkill, unless I'm still sailing at 200 because I've re-used the same one now for about 4 years. I just cut the flattened end off and refill but will probably need another straw in about 5 years. :D
 
ASAP do a spurious version of the radice marketed as Orbitrade. Here Search | ASAP Supplies
Get the one with a grease point and a water feed. You don't need to connect the water feed to a supply for a slow moving vessel. Just take a bit of hose up above the water line and burping will not be necessary when the boat is relaunched. As for doing it afloat I don't think that is possible
 
laika said:
Interestingly I've just been reading that these seals are supposed to be greased once a year. Despite the company that originally fitted it doing a fair bit of work ashore 2 years ago (incl. replacing cutlass bearing) they didn't mention the stern gland. I'm presuming this is something I should have been doing every time I've hauled out...
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My initial thought was whether regular lubrication had been carried out as these seals do thousands of hours on work boats. They should and also regularly burped to release air around the seal and ensure water at the seal. Yours is currently Auto Burping. I suspect that the correct application of the correct grease now will get you to your destination with minimal leakage and it is highly unlikely there there will be a failure or major inrush. Just need a sponge from time to time.
 
Never Grumble said:
How far do you need to push the straw in to grease properly?
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I said about 20mm in post #10 but think that's actually too far and 15mm would be fine. My notes are on the boat in Greece and I've obviously skipped 2 launches now. Last time I greased it would be early 2019. I think that one seal was approx. 2.5mm from the end and the next was about half that distance (i.e. 1.25mm). That would make the mid-point about 1.9mm and makes my first guess of 2mm and second estimate of 1.5mm sound reasonable (my boat has a 30mm diam. shaft).

I put the straw in too far when I first used it, probably 30mm. I found that I was burping every few weeks and re-greased properly to solve the problem. I measured the distance to the first and second seal when replacing the seal and kept a not. It's a 5 minute job to put a mark on the straw, fill it with about 1.5ml and squeeze most into the seal. I also have a mark on the straw to show approx. 1.5ml (measure internal diameter of straw, and calc. Pi x R^2 x h). :D

Just a pity that all these detailed notes are on my boat.
 
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