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Stern gland indentification


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No idea who supplied it.  Looks like an early Springer one in some ways.

 

To repack:  grease well.  Hold the front hexagon.  Turn the aft most hexagon clockwise a couple of turns or as far as it goes.

  Turn the front most hexagon anti clockwise till it comes off the stern tube.

 

Ferkle out the old packing.  A bent scriber and a carpenters gimlet may help.

  Fit new packing. At least two turns, joints opposite each other.

Refit the front nut and tighten clockwise gently so you can just feel the packing begin to drag on the shaft when you turn it by hand.

Tighten the aft nut anti  clockwise to lock the front.

 

Grease it well, again.

 

Run the engine in gear gently, for about 15 minutes.   Check that the nuts don't get hot and there is about 1 drip every 20 or 30 seconds from the stern tube.

Adjust (loosen if hot, tighten if too wet), as needed.

Repeat check.

No

 

Job done.  Have a wet.

 

  if the aft nut won't separate from the front bit, screw the whole lot off  forwards (anti clockwise). Then go from Ferkle.

N

 

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15 minutes ago, rgriffiths said:

That is great - thank you. Do I assume the same kind of packing as the more common type (as long as I get the right size).

 

And why is there grease coming out at the back as in the picture? I can't see what should be preventing this.

Yes, the same type of packing. its probably up inside the nut but when the nut comes off you might find a pusher in which case the packing is down the tube.

 

The grease is coming out of the back of the gland because the thread where the gland screws onto the shaft is not sealed. As long as its not leaking water its probably best to leave it and just wipe the grease away now and again. I would not like to try to unscrew the assembly to reseal it with the boat in the water.

Edited by Tony Brooks
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Use standard packing.  No idea what size though.

The grease at the back is maybe coming from the hole in the outer tube where the bearing metal retaining peg is formed.  Sometimes the bearing is poured into the tube  via this hole, and then machined internally, sometimes the bearing metal is poured in from one end and a peg forms in the hole.  Clean the grease off and take another pic and it may be possible to say more.

 

Or the grease is coming down the thread where the tube is screwed into the stuffing box.  The answer then is to unscrew the whole stuffing box and wrap the thread with PTFE tape  before refitting.  Not a job for the inexperienced to do while in the water.  Until you are on dock no harm will come from just wiping the grease off when there is enough of it.

 

Beaten by Tony.

N

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2 minutes ago, Tracy D'arth said:

Gland packing is put in in separate complete rings, joint staggered. Never a spiral because a spiral will tighten on the shaft and groove the shaft.

That is something else we will disagree over given certain fitting precautions are followed. Unless they get pre-cut packing I would submit the average boater is more likely to cause leaks by packing in rings that putting a coil in so it acts as a scroll when in ahead and the gland is not over tightened. On no account to be done on a yellow metal shaft though.

 

I learned this on the hire fleet when if a Saturday engineer packed a gland  I would end up going upriver to sort it out on about Wednesday. It did not happen if they packed in a spiral and the shafts did not wear excessively.

 

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14 minutes ago, Tony Brooks said:

That is something else we will disagree over given certain fitting precautions are followed. Unless they get pre-cut packing I would submit the average boater is more likely to cause leaks by packing in rings that putting a coil in so it acts as a scroll when in ahead and the gland is not over tightened. On no account to be done on a yellow metal shaft though.

 

I learned this on the hire fleet when if a Saturday engineer packed a gland  I would end up going upriver to sort it out on about Wednesday. It did not happen if they packed in a spiral and the shafts did not wear excessively.

 

Sorry Tony in this instance I must disagree with you.

I have seen shafts that have been ruined by spiral wrapping packing, usually too thin in section because it is easier to put in. One way or the other it will tighten on the shaft, compress hugely and then leak. The owner tightens the gland and the situation continues till the shaft is grooved.

 

The trick with gland packing starts with getting the correct cross sectional size.  Then cutting rings with a splayed cut, preferably at right angles to the shaft, that fit exactly around the shaft.

Greased whether it is carbon or PTFE impregnated and tamped one at a time using the pusher, next ring staggered joint and repeat till the gland is fully loaded.

Pusher fitted, nuts nipped until the shaft just drags.

 

Done this way the gland will not leak, will not groove the shaft and will adjust as required to be leak free for many hundreds of hours.

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That is all fine  but its achieving the exact length for the shaft without fraying the ends that causes problems. If the boater can cut cleanly and accurately then I agree, put rings in but its a skill that few new boaters seem to posses. 45 boats over 10 years in hire use and I found no evidence of excess shaft wear on stainless shafts. Probably a lot depends upon how tight the gland is adjusted.

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5 minutes ago, Tony Brooks said:

That is all fine  but its achieving the exact length for the shaft without fraying the ends that causes problems. If the boater can cut cleanly and accurately then I agree, put rings in but its a skill that few new boaters seem to posses. 45 boats over 10 years in hire use and I found no evidence of excess shaft wear on stainless shafts. Probably a lot depends upon how tight the gland is adjusted.

I bow to your valuable experience.

I will continue to do things my way however, I'm a difficult old biddie.

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Just now, Tracy D'arth said:

I bow to your valuable experience.

I will continue to do things my way however, I'm a difficult old biddie.

I would never advise someone who is competent to spiral the packing in and I don't do it myself but I think there is a place for it while newbies get to grips with packing and gain confidence.

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I have only spiralled once, when the back ends design meant you couldnt actually get down there to cut the packing on the shaft, or even get fingers near.

The old packing was removed with a heath Robinson style pick on a stick ......the new packing inserted using a large flat blade screwdriver.

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Small corkscrew for getting the old out. Rolcut pruning shears for the cut.

 

A bit of maths will work out the length of each piece, 2 PI R, shaft diameter times 3.14.

 

Or wrap around a stick/bottle/pipe of the same diameter as the shaft.

 

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