Stern tube grease nipples

[ShipsWoofy]

Before I left the boat I had to add some more packing to the stbd tube and greased both of them, port was fine but I had a problem with the stbd side. When I tried to squirt the grease gun, grease came out around the threads at the bottom of the nipple assembly (many occurrences of the word nipple to allow people to snigger).

Surprisingly I was actually able to unscrew (oh behave) the assembly to find it has become quite thin, it appears to made of mild steel, at least that is what it feels like, many years of grease has turned it black..

My question, as I forgot to measure the thread, is there a standard size for these things, I expect it to be imperial thread and diameter due to the probable age. I can of course measure it, but would like to try to source one today locally. I may even convert it to one of those screw down pots rather than a nipple.

Description, it is a tube about an inch long and about an inch diameter closed at the top with a grease nipple, fitted to a 1" diam shaft old style stern tube. Having never had a problem with one of these things I have never had cause to examine or even source one. Would say, a waggon axle use a similar unit, or will I need to visit a marine engineers.

Many thanks in advance.

 

[eyehavit]

Hopefully a common greaser and the only choice to make is whether the thread is metric or imperial. The nice shopkeeper might let you take one of each and return the unused.
Good luck.

 

[tillergirl]

See here for a remote greaser http://www.tnorrismarine.co.uk/offers.php
or here http://www.tnorrismarine.co.uk/sterngear.php for screw down 'pots' I think Norris machine/make these so they might sell you the bit to insert.

 

[Andrew_Fanner]

There is every chance that the thread is NPT, an American tapered thread for pipes, or the British (non compatible) equivalent. How old is the setup? Newer stuff should be metric. I'd take it into an engineering supllies type place and try the "one like this" approach. An agricultural machinery place may be able to help.

 

[cliffordpope]

Usually when grease leaks out round the nipple on something rather than going into the shaft housing it is because of excessive back pressure caused by a blockage. It would be worth investigating that first.
If the thread is sound and the nipple is holding tightly, not about to fall out, you could try cleaning it up thoroughly and using a hard-setting sealer or bearing adhesive - something like Locktite?

 

[ShipsWoofy]

Yes, I will try cleaning it, but I would rather not seal it down as that will be a little final. My worry is that it has corroded, although it has not yet cracked, it is thin enough that I believe I could squeeze it and crush it. The corrosion which we have all seen on stuff in the past, is at the stage that the edge of the metal is as thin and sharp as a razor blade. They need to be replaced.

I will measure it properly on my next visit, I am not happy about taking it off the boat for any appreciable time.

EDIT>>

It looks like this, but has a nipple on top. I think also, the bottom wide part of the thread is actually part of the packing box, rather than screwed into the original nipple thread as this one appears to be.