Stern tube greaser - how to use one?

[Bilgediver]

What is the greaser supposed to lubricate? Stern gland, cutless bearing, stern tube? It sounds as though many sailors forget or don't bother to grease without dire consequences.

Depends what is fitted.......

Some boats have a white metal cutless at both ends of the shaft plus packed gland at gearbox end.......This needs grease at both ends so lots of screwing

Some boats have a rubber cutless at prop end and bronze or white metal bearing plus packed gland at gear box end This needs less screwing as no grease required at rubber cutless

Some boats have a rubber cutless at prop end and just a packed gland at gear box end. This leads little screwing.

Some boats have a rubber cutless at prop end and bronze bearing and Dripless seal at gearbox end. This needs very little screwing.

Some boats have a rubber cutless at prop end and Dripless at other. No screwing generally though some Volvo seals like a dab of grease at the start of the season.


Seems you need to know what is fitted before going mad with the greaser

 

[sailorman]

It's interesting to read that a lot of people grease when stopped. It is fairly standard practice at sea to only grease when the shaft is rotating. This way the shaft distributes the lubricant around the shaft as you add it and there is zero chance of over pressuring one side of the shaft with too much grease and thus risk damaging the shaft line components.
As to how much? On a small vessel with greasing points on the shaft you would generally give the points a couple of shots of grease every week if running all the time. So on a yacht? 2-3 times a season?

For the leisure user, clockwork auto greasing capsules may be an easier option. Simply wind them up and they add as required until their empty.

my engine is flexibly mounted, there is a R&D coupling as well.
the only bearing holding the shaft in alignment is the P bracket, so effectively the shaft is floating & i doubt that a little grease from one side will make much difference to a 32m/m s/s shaft

 

[chewi]

I turn it until it goes stiff after motoring.

On the subject though, trying to fill it up, I get grease all over my hands trying to poke and squelch it into the greaser, and lots of air pockets where I haven't managed to poke it enough. Am I doing it wrong?

THe grease tub has a cover with a hole so you can squeeze it down to make a sausage shaped lump of grease, but it still doesn't go in easily . Does anybody have a clever dodge - for instance, could freezing a sausage thus produced make it easier to get into the greaser?

My greaser was a brass cylinnder with threaded ends top and bottom,, the piston was screwed into the top
With the piston fully retreated I then unscrewed the bottom and put that end against the finger ring in the grease pot,.
pushing the cylinder against the finger ring delivered the grease directly into the cylinder.

 

[captainboo]

Depends what is fitted.......

Some boats have a white metal cutless at both ends of the shaft plus packed gland at gearbox end.......This needs grease at both ends so lots of screwing

Some boats have a rubber cutless at prop end and bronze or white metal bearing plus packed gland at gear box end This needs less screwing as no grease required at rubber cutless

Some boats have a rubber cutless at prop end and just a packed gland at gear box end. This leads little screwing.

Some boats have a rubber cutless at prop end and bronze bearing and Dripless seal at gearbox end. This needs very little screwing.

Some boats have a rubber cutless at prop end and Dripless at other. No screwing generally though some Volvo seals like a dab of grease at the start of the season.


Seems you need to know what is fitted before going mad with the greaser

Mine has a white metal cutless at the prop end and a bronze bearing with a packed gland at the gearbox end - different to all the above!

So how much screwing do I need to do!?

Generally I have just given it a turn every now and then and so far it now runs reasonably cool to the touch and doesn't leak water or grease so hopefully it is just right but I still wonder if I am putting too much or not enough grease down it for the white metal bearing section.

 

[cryan]

i doubt that a little grease from one side will make much difference to a 32m/m s/s shaft

You would be surprised!
If you look at this link( http://www.lubeline.co.uk/Downloads/grease_guns.pdf ) you will see that the standard duty hand pump grease gun type F101 develops 4300psi or 296.5bar. To put that in perspective the original hydraulics fitted to Tower Bridge in London lifted the bascules with 750 psi or 50bar. So just think what 4300psi can do to an 32mm stainless shaft?

 

[sailorman]

You would be surprised!
If you look at this link( http://www.lubeline.co.uk/Downloads/grease_guns.pdf ) you will see that the standard duty hand pump grease gun type F101 develops 4300psi or 296.5bar. To put that in perspective the original hydraulics fitted to Tower Bridge in London lifted the bascules with 750 psi or 50bar. So just think what 4300psi can do to an 32mm stainless shaft?

i an not applying grease with a grease gun but a light hand pressure to the remote greaser cruciform screw

 

[chewi]

I thought that was how it was supposed to work. In our case though, the greaser is in a corner so the tub won't fit over it.

so take the greaser to the pot instead, unscrew the cylinder from the bottom end, leaving the piston in situ.

 

[sighmoon]

so take the greaser to the pot instead, unscrew the cylinder from the bottom end, leaving the piston in situ.

First wind out the handle so the full lenghth of the threaded push rod is exposed,but do not remove the cap.
Next grasp the greaser body in your hand using a rag to stop it slipping,and unscrew the whole greaser body from the fitting which is screwed down. The first time you do this it will be tight because it has paint on it or has been overtightened,so you may need an oil filter removing tool eg strap wrench.
Turn it upside down and put in grease,I use a knife from the galley, and *gently* tap the greaser handle on deck, the grease will fill up the greaser as if by magic with no gaps,no prodding down the grease,no mess.
When it is full,screw it back on,don't overtighten.
I found this method by accident due to overtightened threads on the cap by the way cheers Jerry

Edited to add,I turn it until it gets stiff,then another couple of turns,before motoring,and before leaving the boat unattended for a while.
Thin grease lets a drip through,thick grease doesn't, I found a massive pot of 70-yr old lift machinery grease,seems to work well and smells weird,made from whales perhaps!

The last greaser I had, the tube actually unscrewed at the base. You lifted it off, placed it in the grease tin, wound the plunger back up and it drew in the grease. Then just screwed it back onto the base.

Got it. Thanks!