Stern gland greasing - why?

[Ubergeekian]

OK, this is a bit of an embarrassing question, but here we go.

I'm about to have my stern gland overhauled, and have been strongly advised by several people that it would be a jolly good idea to fit a remote greaser. I'm not doubting the advice - but I'm puzzled, because I don't know what they do.

The stern gear is a cutlass bearing (which I understand is water lubricated) and a stuffing gland type seal, and the greaser, as I understand it, squirts grease in between them. Why? The cutlass bearing doesn't need it and squirting grease onto the shaft doesn't seem a very efficient way of doing something to the stuffing gland.

Clearly I have not just realised something which has escaped thousands of people in the past - I must be wrong. But what am I missing? Help!

 

[Obi]

I think and I do mean "I think" it is because it needs the grease to make the seal fully sealed. Not very eloquently put, sorry.

I also think it helps keep the stuffing in the box in good condition and lubricates the internals.

Thats my ignorance of these things.

If it requires greasing, it should have a method for greasing it already. If its one of those brass caps (about the size of a 50p) that you fill with grease and turn periodically, then I would consider an alternative.

I have an angled grease nipple on mine, it costs 30p to renew the nipple and I just plug a grease gun (cost £12 from MotorWorld) onto it and give it a squeeze of grease every few trips. I dont think the automatic ones or the ones that are fitted in situ are really worth the money, I think it was about £80 for the kit I looked at.

Mark

 

[aquaplane]

First off, the Cutless bearing is a rubber jobbie that's water lubricated and cooled and outside the hull, in the "P" bracket on most boats if I understand right, not on mine though, it's bolted to the hull just infront of the prop.

The stuffing box is the thing that lets the prop shaft go through the hull but keep the sea out. & coz the stuffing box likes to be intimate with the prop shaft ( to give a good seal and keep the sea out) it needs to be lubricated to stop it geting warm and wearing, so you grease it.

To be honest, I only give the screw on the grease thingy a ½ turn when I remember on my Centaur, but I do remember most times I run the ingin and it's only a small turn before the screw gets stiff.

 

[LittleSister]

I am not too up on it, but my understanding is similar to previous poster -the stuffing gland has cotton or similar based packing which needs grease to keep a waterproof seal and make the packing last.

When we bought our present boat it had a little greaser (50p sized screw top, and holding about a tablespoon, max, of grease) attached directly to the gland. Operating this (I was told do it every time I started engine, and after each few hours under engine) required half emptying our cavernous cockpit locker, removing a few wing nuts, lifting out the inspection hatch, then hanging upside down in the locker to reach down to the stern gland and turn the screw cap down a few turns to force a little grease through. Refilling it (not an infrequent job given the tiny size of the reservoir) involved similar while you removed the whole body of the greaser, praying you don't drop it in the bilge -particularly tricky while trying to get the thread started to re-attach it.

I initially baulked at the £76 quid I was asked for the remote greaser kit, but it has proved to be one of the best boat purchases i have ever made, transforming what was a complete (and frequent) pain in the transom to an easy job I hardly notice (a quick twist of the knob just under the cockpit locker lid - takes seconds). Reservoir is so big it only needed refilling once, I think, in a year in which we did best part of 2,000 miles, often under engine.

 

[ianabc]

Miracle green goo reduces friction...

There appear to be two up to date methods to ensure redduced ingress of water through the stuffing box.

They are (1) regular flax packing and teflon gree Goo packing ( we used this)

or

(2) Gore new synthetic flax packing with the goo in the fibre


We have installed a green low friction GOO that is teflon based and is reputed to allow for cool running of the stuffing box and no leaks at all.


It appears to work well after one season of use.

It does require the three rings of flax with offsets in the ends of the individual rings.

The promise of the manufacture has been kept in that there are few drips except to ensure that the box runs cool to the touch.

I believe that over tightening will lead to hot running and the material oozing out.

Link to almost drip free packing / gore

www.e-marine-inc.com/products/gfopacking/packing.html.


Link to stuffing box instructions and to Gore packing:

www.pbase.com/mainecruising/stuffing_box.

www.sailnet.com/forums/gear-maintenance/11725-dripless-moldable-packing.html

 

[PerformanceSailor]

Consider a change...

For your next birthday, ask for a PSS shaft seal. No more packing, or grease, or water ingress. I put one on in '95, and the only regular maintenance so far was replacing the bellows in '07, per factory recommendation. Having a dusty-dry bilge is a good thing.


I know that well-proven, time-honored tradition is also a good thing, but this product has been a great upgrade for me.

LB

 

[sailorman]

For your next birthday, ask for a PSS shaft seal. No more packing, or grease, or water ingress. I put one on in '95, and the only regular maintenance so far was replacing the bellows in '07, per factory recommendation. Having a dusty-dry bilge is a good thing.


I know that well-proven, time-honored tradition is also a good thing, but this product has been a great upgrade for me.

LB

he has already been there in another post.
owing to the very restricted nature of his "Canoe" stern he is considering a remote greaser

 

[markdj]

We have 2 shafts on half cutlass bearings held with p brackets on clutlas bearings. The shaft is sealed at the half cutlass by a stuffing box with no grease involved. The half cutlass has water injection which puts water from the engines around the rubber area of the cutlass.

 

[vyv_cox]

OK, this is a bit of an embarrassing question, but here we go.

I'm about to have my stern gland overhauled, and have been strongly advised by several people that it would be a jolly good idea to fit a remote greaser. I'm not doubting the advice - but I'm puzzled, because I don't know what they do.

The stern gear is a cutlass bearing (which I understand is water lubricated) and a stuffing gland type seal, and the greaser, as I understand it, squirts grease in between them. Why? The cutlass bearing doesn't need it and squirting grease onto the shaft doesn't seem a very efficient way of doing something to the stuffing gland.

Clearly I have not just realised something which has escaped thousands of people in the past - I must be wrong. But what am I missing? Help!

If the packed gland is working well without dripping excessively, up to around two drops per minute seems to be the recommended figure, if the shaft can be turned easily by hand, and if the shaft in way of the gland is not excessively worn after some years use, then I would say you have absolutely no need for a greaser.

 

[Obi]

If i had to make your decision it would be based on the following:

1. How hard is it to access the stern glad. If it is hard to access one like littlesisters, then definately the £76 is well worth it.

2. Do you have anything else with grease nipples that requires a grease gun? Steering cables perhaps? Rudder stock? If there is a requirement for a grease gun else where, AND your stern gland is easy to access I would go for the grease gun. If memory serves, all stern glands will have a place to grease them on, so if you decide the gun is for you all you need is a a method to fit a grease nipple on here. I think my previous owner had a 1.5 inch (length) brass thing drilled out, and then threaded for fitting. Must have cost him about £3. Ask or PM if you want more details/photos.

If all this is too much faffing and your stern gland is easy to access, then you could just go for the turny cap thingymajig that is often standard.

Of the 21st century solutions that require little maintenance as mentioned.

Mark aka Obi.

 

[Ubergeekian]

If i had to make your decision it would be based on the following:

1. How hard is it to access the stern glad. If it is hard to access one like littlesisters, then definately the £76 is well worth it.

Absolute living hell to reach. The only access is over the top of the engine. This is one reason that I am paying Windjammer - who have a skinny engineer on the books - to do it.

2. Do you have anything else with grease nipples that requires a grease gun? Steering cables perhaps? Rudder stock? If there is a requirement for a grease gun else where, AND your stern gland is easy to access I would go for the grease gun. If memory serves, all stern glands will have a place to grease them on, so if you decide the gun is for you all you need is a a method to fit a grease nipple on here.

This is the bit that puzzles me - they tell me that there is no greaser of any sort (screw down, nipple, whatever) on the stern gear at the moment. So what does adding grease into the system do?
If all this is too much faffing and your stern gland is easy to access, then you could just go for the turny cap thingymajig that is often standard.

Of the 21st century solutions that require little maintenance as mentioned.

Mark aka Obi.[/QUOTE]

 

[Pete735]

Stern Gland

I posted almost the same question on here on 20 Dec 09, (search for "stern gland question" will find it). If you go back and look at it, my conclusion was the greaser is probably a throwback from an earlier type of system and probably not necessary today for the reasons you indicate. Having said that I also admitted that I would continue to use the greaser, because it was there and convenient to do so!

 

[Poignard]

On my boat the inboard bearing is white-metalled and that needs greasing. The outboard bearing is a Cutless type lubricated by water.

 

[Amp1ng]

Stern Gland Adjustment

Whilst on the subject of Stern Gland Overhaul. How often should one expect to leave between full inspection of stern gear between seasons and what should be the focus of attention when inspecting?

I have a remote greaser which I turn before starting the engine every time I go out, visual inspection during the season revealed a slight increase in the amount of water seepage but still only a tiny drible over a couple of weeks. Whilst out of the water this winter I plan to check adjustment of the gland. Whats the best way to do this?

Thanks

 

[sailorman]

Whilst on the subject of Stern Gland Overhaul. How often should one expect to leave between full inspection of stern gear between seasons and what should be the focus of attention when inspecting?

I have a remote greaser which I turn before starting the engine every time I go out, visual inspection during the season revealed a slight increase in the amount of water seepage but still only a tiny drible over a couple of weeks. Whilst out of the water this winter I plan to check adjustment of the gland. Whats the best way to do this?

Thanks

i turn every time i close the engine down to stop water ingress

 

[alahol2]

Whilst out of the water this winter I plan to check adjustment of the gland. Whats the best way to do this?

I do it every year, it's basically a case of tightening up until you just start to feel the propshaft 'tighten up'. Still turnable by hand but with a slight resistance. Also agree with sailorman, give greaser a turn when you shut off engine. May be a turn every few hours if motoring continuously.

 

[Amp1ng]

Still turnable by hand

it's basically a case of tightening up until you just start to feel the propshaft 'tighten up'. Still turnable by hand but with a slight resistance.

I presume stil turnable by hand means shaft disconnected from engine and by gripping the shaft itself?

 

[moluag]

I do it every year, it's basically a case of tightening up until you just start to feel the propshaft 'tighten up'. Still turnable by hand but with a slight resistance. Also agree with sailorman, give greaser a turn when you shut off engine. May be a turn every few hours if motoring continuously.

I use the remote greaser when i remember,i have had the boat for 10 years and have never tightened the gland maybe this year i should check it out as the engine is out for an overhaul,i dont get much water in either,even though its weeks sometimes between visits is this unusual ie not tightening the gland

 

[sailorman]

I presume stil turnable by hand means shaft disconnected from engine and by gripping the shaft itself?

still connected, out of gear, engine NOT running
mine turns by hand on the coldest of morning & rarely drips

 

[DerrickHigton]

Stern-tube greasing

Not all stern-tube arrangements require greasing. My sailing boat has an arrangement common on work-boats, with a Cutless bearing at the outer end of the stern tibe. Some of the engine cooling water is piped to the gland and passes through the tube, lubricating the bearing. The gland itself is attached to the stern-tube by a 4" (100mm) length of special rubber tube and relies solely on the packing (and the Jubillee clips!) for a seal. Over 30 years I have had few problems.

I do experience more wear on the gland than on the bearing. I occasionally (at about 7 yar intervals) pull the shaft and machine a few 'thou' where the gland touches. It is not difficult to squeeze the packing back down to the slightly reduced diameter once reassembled. Every fifteen years or so I make a new shaft in NAB (nickel alluminium bronze).

I doubt whether grease and Cutless bearings are compatible and suspect that greasers are a legacy of the days when metal bearings were used.

So long as you re-pack the gland when it runs out of adjustment, you should have few difficulties.