Stern Gland

[cindersailor]

This is going to be a bit tricky to describe, but here goes. Having just installed the 1GM I have been tinkering with in the garage for the winter I am quite happy that it runs sweetly and is not squirting oil or water into the bilge. However, the inner part of the stern gland is running hot - almost too hot to touch after a long run, and this when the gland nut is only hand tight. I have loosened off the nut until a turn on the greaser allows grease to ouse past the threads, this lowers the temperature, but it still gets warm and I am concerned that the imperfect seal for the grease means that it is not being forced into the stern-tube and outer bearing. I should mention that the outer shaft bearing is not a cutless type, but rather a close fitting bronze one which I assume is supposed to be lubricated by the greaser. It appears to have the advantage that it does not allow any water through the stern tube.

I did not replace the original gland packing as it seemed to be looking good. Having done some research I can only find descriptions of stern glands that have the packing inside the gland body and this is compressed by a collar which fits inside the the body and is forced into the packing as the glad nut is tightened. However, the packing in my stern gland is contained in the cylindrical gland nut, and there is no room to fit any packing into the body of the gland which is a close fit around the shaft. If I completely unscrew the nut it is quite, although not completely, free to turn on the shaft.

The obvious solution seems to be to replace the packing and not to use so much so that I can screw the nut on further before it gets compressed. But I wanted to see if anyone is familiar with this design of stern gland and its peculiarities.

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[Graham_Wright]

If the outer bearing doesn't allow water past it, why bother with an inboard gland?

It could be that the inner gland also needs to be wet to stop it overheating.

Graham Wright

<hr width=100% size=1>GBW

 

[pete]

Hi
Just a thought how is your engine allignment ? could the shaft be bending as it enters the stern gland causing side loading on the gland.

Pete

<hr width=100% size=1>Artificial intelligence is no match for natural stupidity

 

[webcraft]

My gland is slightly warm and does not drip - I thought this was a good thing?

- Nick

<hr width=100% size=1><font size=1><A target="_blank" HREF=http://www.bluemoment.com>http://www.bluemoment.com</A></font size=1>

 

[Guest]

Certainly not an expert on this but ...

To have a gland with NO water drip at all - isn't that unusual ? I always considered that the gland should have some water albeit tiny amount only as cooling and lubrication on the outer part .... the grease being a 'lub-agent' for the packing only.

My packing runs warm - well it did when the bloody engine worked !! - but not hot.

Maybe we should all change to 'dripless' stern seals ?? Then supposedly all our woes will stop ----- yeh ?


<hr width=100% size=1>Nigel ... and of course Yahoo groups :
http://groups.yahoo.com/group/gps-navigator/

 

[TonyBrooks]

Yes - very common on flexible glands used with P or A brackets.

Pack it just as the sort with a "pusher" under the nut (but make double sure you do not have a pusher that is so far in, it looks as if its part of the tube.

In my experience of stainless shafts as long a sthe gland is nipped so thet it just stops dripping there is no problem, but never do more than just stop the drip. Usually when you do this using the greaser forces a drip from the gland.

Glands do run warm, but should not run hot enough to be uncomfortable, so I would also suspect the engine is to lined up correctly or the shaft is bent.

Tony Brooks

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[mickshep]

Hi Philip. I packed The stern gland on Fosca on Friday and found that she is fitted with what sounds like an identical gland.
My problem was that the gland would begin leaking within a very short while of getting under way and required copious amounts of grease to remain watertight. When I dried out the boat on friday I also found that there was no way to put packing in in the normal way due to the very tight fit between the shaft and it's tube.
After cleaning out the grease in the gland nut I found a groove the same size as the strip of packing that came with the boat, but with only enough room for one ring as apposed to the usual 3 or so on a 'normal' gland.
I fitted a single turn of the packing and made the cut at 45 deg so as to minimise the risk of water getting through.
I then tightened the nut up whilst turning the shaft by hand to guage the amount of pressure the packing was putting on the shaft.
Since Friday the boat has travelled aprox' 50 miles, all under engine with no overheating problems and more importantly no water or grease entering the boat.

<hr width=100% size=1>My Mum say's I'm not a fat b@st@rd, just heavy boned.

 

[cindersailor]

Thanks all for the comments. I checked last night that the compression collar had not been forced so far into the gland that it appeared to be part of the body as suggested by Tony B (not thought of that possibility), but its just solid bronze! Dug out the existing packing and replaced it with some new which appears slightly smaller. So far so good. Still gives a seal, but now only warm, not hot after a run.
Phil

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