Volvo penta stern gland seal.

[dignity]

I have a Volvo Penta shaft seal/stern gland, which has started to leaking when using the boat, however it stops leaking completely when not in use. I can live with it leaking when in use, but is it likely to suddenly start leaking when not in use. I don't really want to have the boat hoisted out again, it's only just gone back in.

Any thoughts would be appreciated.

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[pandroid]

Never heard of this before. Volvo claim they should be changed after 5years, but most people seem to reckon 10. There was an extensive thread on this some time ago <A target="_blank" HREF=http://www.ybw.com/cgi-bin/forums/showthreaded.pl?Cat=&Board=pbo&Number=491154&page=&view=&sb=&o=&vc=1#Post491154>here</A>

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[alan]

Have you greased it as per VP instructions?? If I remember correctly you should use about 2 cm of the VP special blue grease once a year.

Alan.
Nettuno, Italy.

<hr width=100% size=1>Alan Cloke

 

[malcp]

Is the shaft / engine alignment ok?
Any untoward shaft vibrations?

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[alan]

Second thought: Have you tried tightening the jubilee clips which hold the seal on the "hull" ?? Is the water coming from the shaft/seal interface (moving parts), or the seal/hull interface (fixed parts).

Alan.

<hr width=100% size=1>Alan Cloke

 

[dignity]

No smooth as a bird, everything was alright until I changed the cutlass bearing, then it started leaking, looks like the whole lot will have to come out, the part isn't expensive it's just all the hassle.

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[steve_cronin]

You may have no choice.

One thing people omit to do is clean the prop shaft where the seal bears on it. Since this is within the seal body/sterntube you have to fit the red plastic protective sleeve, undo the shaft clamp out of the gearbox and slide the shaft backwards. This will likely reveal a coating of calcium on the shaft which needs to be removed. It extends right up to where the seal lips sit on the shaft and causes it to lift off ever so slightly in rotation, hence your leak. Great care must be taken however not to damage the shaft even slightly in the area where the lip sits as any ridges or other protrusions will themselves damage the lip. Brillo pads used on the shaft are best. Only use a sharp scraping tool as a last resort and then very sensitively but still finish off with the soap pad.

These seals drip on some boats for years before it gets to happen when stationary. My guess though is that it will clear up when the shaft is cleaned. It always did with the two i had.

Steve Cronin



<hr width=100% size=1>The above is, like any other post here, only a personal opinion

 

[Trevor_swfyc]

This part will cost about seventy pounds so its not cheap. When you replaced the cutlass bearing did you remove the shaft or just the prop. As you should use a plastic insert that protects the lips of the seal when inserting the shaft into the seal.
If you dried the boat out you could slide the seal along the shaft to inspect the shaft for calcium deposit as previously pointed out. You would still require the plastic insert to push the seal back home afterwards else you might damage the seal.
You say it is not leaking while at rest, so have you actually watched it drip while motoring, I say this as I thought mine was leaking and replaced it only to find the pipe that connected the salt water to the back of the gearbox had a pin hole. The water collected below the stern seal which made me think it was from there.

Trevor

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[mldpt]

its also worth checking the diam of the shaft, when I bought my boat 14 years ago the engine had been run badly out of line, so I lined it up and fitted a new Volvo seal and experienced the same trouble you have, I tried everything for years to stop the thing dripping when motoring, until one day, I was a bit bored so I made up a bush to fit over the shaft and into the stern tube, uncoupled the shaft removed the seal, wosh a gallon or two of sea water came in I sliped the bush onto the shaft and into the stern tube, ( boat still in the water) this stoped the ingress of water. I put my Micrometer on the shaft to find it was warn .010 " and out of true ( I assume this was due to dissalignment before I bought her. I extended the stern tube back into the engine room and refitted the seal so that it now runs on a smoth unworn part of the shaft, I have not had a drop since. fortunatly on MY westerly corsair there is plenty of space between gearbox and seal so its reasonably easy to work on in this way. I reckon I shipped about 2 gallons changing the stern gland this way, but its not the safest way I gues.
Mike

<hr width=100% size=1>www.sailingforfun.co.uk

 

[steve_cronin]

Micrometer - not directly related....

I think that a micrometer (or at least a pair of callipers) are a very useful addition to the toolkit of any boat. I can think of many times when accurate measurement or size matching would have gotten me out of trouble earlier.

Steve Cronin



<hr width=100% size=1>The above is, like any other post here, only a personal opinion

 

[willothewisp]

agree. first thing is grease it by using the sprecial blue grease, then, after running the engine, squeeze the gland. A slosh of water will come out, but after this it ought to be dry.
Nobody ever told me to grease it, so I had the same problem.
Coby

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[Trevor_swfyc]

My problem was the opposite I was told to grease it but not how much. I was putting in 50 cc / yr over 10 years I had nearly filled the complete stern tube and it still worked. Only found out the correct dose was 2 cc when I decided to fit a new seal and got my hands on the instruction sheet.

Trevor

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[abraxas]

I had the same problem so I had a new seal fitted and the cutlass bearing changed at the same time. All this work was carried out by a Volvo service centre. Now it leaks when moored as well as when in use. Nobody has ever told me about grease or squeezing the seal to let water through. I will try the latter next time I am on the boat. I will let you know if it helps.

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