Photo competition - stern gear

[paulcatchpole]

Hi all,

 

Right, photo competition time...

 

What am I going to find when I remove this carefully fastened washing-up-liquid bottle?

 

Right, update time!

 

First thing to be seen after removing the plastic bottle is:

 

 

This is, it seems, fibreglass exhaust tape, soaked in something like vaseline... No, really!

 

 

After cleaning this up a bit with a cloth, and having a feel around, this is the damage...

 

 

It's a bit odd!

 

It's down, round one side of the tube, which looks like it can't turn in normal use, cause of the two bolts holding it into the stern end plate.

 

So what caused this then?

 

And how do I fix it? Brazing, if I take it off the boat - and how do I get it off - two nuts off the inside of the stern plate, prop is off already - then does it unscrew from the stern greaser assembly?

 

 

The other thing I wanted to ask, was, is the reduction box output supposed to have lash in its connection to the driveshaft? Cause it does - I can rock the component with my hand on in the next pic, by a few degrees either way...

 

 

Ah well, hope this whole thing gets you thinking!

 

PC

Edited September 19, 2009 by paulcatchpole

[alan_fincher]

Right, update time!

 

First thing to be seen after removing the plastic bottle is:

 

 

This is, it seems, fibreglass exhaust tape, soaked in something like vaseline... No, really!

 

 

POrobably doesn't help you knowing what the mystery bandage was.

 

Hard to tell from the pictures, but could it be something like this......

 

Sylglas waterproofing tape link

[creamcheese]

POrobably doesn't help you knowing what the mystery bandage was.

 

Hard to tell from the pictures, but could it be something like this......

 

Sylglas waterproofing tape link

 

Of course it helps, we may need a lot more of it!

[casper ghost]

It must have had a bad leak..

Are you going to bight the bullet and replace the whole stern system, and I mean a new weld in stern tube too. Got to be the best thing to do..

[alan_fincher]

After cleaning this up a bit with a cloth, and having a feel around, this is the damage...

 

 

It's a bit odd!

 

It's down, round one side of the tube, which looks like it can't turn in normal use, cause of the two bolts holding it into the stern end plate.

 

So what caused this then?

I'm probably being daft, but can't see exactly what the damage is.

 

Is it split or holed ?

 

Is that circular mark the problem.

 

Towards the left it looks like it may have been attacked by Stilsons, large Mole Grips, or something similar.

 

Without actually knowing more, my gut feel is that somebody has attempted to remove it, and (perhaps) failed.

 

But explain what's actually broke, please......

[paulcatchpole]

I'm probably being daft, but can't see exactly what the damage is.

 

Is it split or holed ?

 

Is that circular mark the problem.

 

Towards the left it looks like it may have been attacked by Stilsons, large Mole Grips, or something similar.

 

Without actually knowing more, my gut feel is that somebody has attempted to remove it, and (perhaps) failed.

 

But explain what's actually broke, please......

 

Aye, it's a bit odd eh?

 

The centre of that ring of dots, is a 10mm-ish circle, which is sort-of punched-in, so it's now a circular piece of brass, severed around 3/4 of its circumference, pressed in... Does that make any sense?

 

It looks well badgered, I agree - there're some proper good gouges down it!

 

I'm not sure I can imagine what might have caused the damage though, as it's on the side, and there's no matching ding on the other side, as per the wrench theory?

 

Are they really that thin that they'd be knackered by abuse from a big pair of stilsons? I thought everything boaty was overengineered?

 

It must have had a bad leak..

Are you going to bight the bullet and replace the whole stern system, and I mean a new weld in stern tube too. Got to be the best thing to do..

 

If it's fixable, no! I'm far too tight to replace something that can be fixed!

 

PC

[casper ghost]

Here's mine

 

Where's my washing up bottle gone?

[johnjo]

Aye, it's a bit odd eh?

 

The centre of that ring of dots, is a 10mm-ish circle, which is sort-of punched-in, so it's now a circular piece of brass, severed around 3/4 of its circumference, pressed in... Does that make any sense?

 

 

Looks like there was a hole, and it's had a piece of rod put in to fill it then hit with a centre punch to burr the opening over to stop it coming out, but why? filling the hole like that wouldn't make it any stronger!

[casper ghost]

I would say that the output shaft from the gearbox should not have movement as you descibe, probably just worn.

[PhilR]

This is fascinating stuff. It will probably remain a *crop circle* mystery. It looks like some really hamfisted person has been using an angle grinder and a drill in a confined space.

 

If you can get the tube really clean and degreased I wonder if the cheapest option might be to fill the holes with milliput and then wrap resin impregnated fibreglass tape around for added security.

 

Phil

[paulcatchpole]

I would say that the output shaft from the gearbox should not have movement as you descibe, probably just worn.

 

Aye, I thought as much - looks like it's just rocking due to play on the single keyway that locates it.

 

Looks like there was a hole, and it's had a piece of rod put in to fill it then hit with a centre punch to burr the opening over to stop it coming out, but why? filling the hole like that wouldn't make it any stronger!

 

I think I get what you mean, but what would have caused the hole in the first place - and how much 'free air' is there between the outside of the stern tube and the inside rotating shaft - can't be much? Also, that damage isn't in an easily worked position - I had to blind hold the camera to get that pic - it'll need taking off or at least rotating in place to get near it!

 

PC

[casper ghost]

This is fascinating stuff. It will probably remain a *crop circle* mystery. It looks like some really hamfisted person has been using an angle grinder and a drill in a confined space.

 

If you can get the tube really clean and degreased I wonder if the cheapest option might be to fill the holes with milliput and then wrap resin impregnated fibreglass tape around for added security.

 

Phil

 

Don't forget to put a washing up bottle over it to protect it

[paulcatchpole]

This is fascinating stuff. It will probably remain a *crop circle* mystery. It looks like some really hamfisted person has been using an angle grinder and a drill in a confined space.

 

If you can get the tube really clean and degreased I wonder if the cheapest option might be to fill the holes with milliput and then wrap resin impregnated fibreglass tape around for added security.

 

Phil

 

Lol, I agree - you're probably right on the crop circle theory - very odd!

 

It's a sweepstake here at the moment trying to work out which of the many interesting things may have been the final straw which sunk it!

 

I need to do something about the reduction box, as it's full of black chunky bits in the water-oil-gunge, which can't be right... So that's got to come off anyway - which may mean I can remove the rest of the stern gear from the boat in the same process. If so, I think I'd probably give brazing a go, unless someone can tell me I can't braze a brass tube? I agree a cheap fix would be something like Chemical Metal, which I'm quite a fan of, but I might be a bit twitchy about refloating the thing with it glued back together....

 

PC

 

Don't forget to put a washing up bottle over it to protect it

 

You suspect this idea has been seen before Mr Holmes?

 

PC

[creamcheese]

Don't forget to put a washing up bottle over it to protect it

 

As long as it's a better quality washing up liquid bottle this time. I think the problems came from using cheap, tat washing up liquid.

[johnjo]

As a complete guess but taking into account the stilson type burring and the possible filled hole.

 

Has, as Alan suggested earlier, someone tried to remove it by turning it.

 

Hole drilled to put a 'T' bar in to get some extra leverage whilst also trying to turn it with stilsons or some sort of grips?

 

As I said a complete guess.

[casper ghost]

You can buy the brass stern parts seperately, they should be standard.

What about the engine and gearbox. Is that ok?

[johnjo]

I assume the tube is leaking somewhere along its length? [hence the crap you had to remove] is it that bodged hole? if so, could you not seal over it with 'Plastic Metal' and then put a jubilee clip over it, or would that pinch the shaft.

 

If complete b*llocks I apologise now!

[paulcatchpole]

I assume the tube is leaking somewhere along its length? [hence the crap you had to remove] is it that bodged hole? if so, could you not seal over it with 'Plastic Metal' and then put a jubilee clip over it, or would that pinch the shaft.

 

If complete b*llocks I apologise now!

 

The bottle and fibreglass tape trickery looks to have been just to cover that mysterious hole, in the 'outer' stern tube... So the chemical metal idea would work, as long as it stayed at the surface - if it set with any quantity inside the tube, then I'd imagine the turning drive shaft might knock it to pieces when first started up... If that makes sense?

 

As a complete guess but taking into account the stilson type burring and the possible filled hole.

 

Has, as Alan suggested earlier, someone tried to remove it by turning it.

 

Hole drilled to put a 'T' bar in to get some extra leverage whilst also trying to turn it with stilsons or some sort of grips?

 

As I said a complete guess.

 

I'm quite a fan of that idea - sounds likely! If so, they didn't get too far, as it's only turned through 90 deg, presuming the hole was drilled on top, unless it went back together like this! Doesn't bode well for me trying to get it apart!

 

Do you know how it's supposed to come apart?

 

You can buy the brass stern parts seperately, they should be standard.

What about the engine and gearbox. Is that ok?

 

Hmm, that's not a bad idea...

 

The engine and reversing gearbox are suspected fine, although I've not had it running... Oil is clean in both, and the engine physically turns over - can't be too much more wrong with an old Lister? If I need to pull the cylinders then I'll do so after seeing what it runs like... The reduction box is presumably just a pair of gears, with no cones or anything clever, so I hope it'll be fine when I've cleaned the gunk out and changed the output seal!

 

PC

[PhilR]

Paul

 

I'm full of admiration of your laid back attitude to all this :-) Good luck. BTW - which Lister engine is fitted?

 

Phil

[paulcatchpole]

Paul

 

I'm full of admiration of your laid back attitude to all this :-) Good luck. BTW - which Lister engine is fitted?

 

Phil

 

I suspect I'm mainly this laid back (and not sinking) cause the boat's not in the water - although I admit, Ms CreamCheese has been having kittens about refloating day, what with the three holes in the counter, and self-draining hull design (large hole in bow)...

 

This one has an SR3, with the lister hydraulic reversing box, and separate reduction. It's an ex-Gordon's Pleasure Cruisers craft from '72-'74ish. Now Napton narrowboats I believe?

 

Ta for the good luck wish! We may need it...

 

PC

[Timleech]

You have a style of stern gear which is less common now, based on that made for wooden boats.

The actual bearing will be a bronze sleeve which slips inside the tube, held in place by the outer flange being screwed onto it. It is prevented from turning by a peg through the outer tube, which locates in a slot in the inner end of the bearing.

The brass 'ring' is where this peg is fitted. It looks as though it has been made loose at some stage causing leakage, possibly by someone trying to dismantle brutally and not understanding the construction.

It may well be possible to do a proper repair on your gear but it will need dismantling completely. A replacement sleeve bearing is probably still available if needed, though this style was made to more than one set of dimensions. Not hard for any jobbing machine shop to make you one, anyway.

The half-coupling should NOT be free to move in any way on the shaft, if that is what is happening (I'm not totally clear whether that is what you meant. A little bit of 'backlash' in the gears is perfectly normal). If loose on the shaft, that is BAD and needs sorting properly before something fails. If the bore of the half-coupling has been worn by running loose, you might need to find an engineering shop to bore it out and sleeve it because the Lister type 6-bolt couplings aren't readily available (to my knowledge, but maybe somebody keeps them) off the shelf in the way the standard 4-bolt 4" flanges are.

To summarise, I reckon you need to strip the whole of your stern gear and clean it all up before making final decisions. You might decide you're better replacing the whole lot with modern 'standard' stuff with a weld-in boss for the sternpost.

Your present type has the advantage that the actual bearing is probably proper bearing bronze which can be replaced as a separate item, the current stuff flogged by the big chandlers has the bearing as part of the tube which may be made of some ill-defined brass/bronze material, quite possibly manganese bronze (propellor brass) which is not a 'real' bearing material.

Yours has the disadvantage of being held into the stern post by two bolts, this method can be troublesome if subjected to abuse such as clouting solid objects - including heavy ice - with the prop.

 

HTH

Tim

[paulcatchpole]

You have a style of stern gear which is less common now, based on that made for wooden boats.

The actual bearing will be a bronze sleeve which slips inside the tube, held in place by the outer flange being screwed onto it. It is prevented from turning by a peg through the outer tube, which locates in a slot in the inner end of the bearing.

The brass 'ring' is where this peg is fitted. It looks as though it has been made loose at some stage causing leakage, possibly by someone trying to dismantle brutally and not understanding the construction.

It may well be possible to do a proper repair on your gear but it will need dismantling completely. A replacement sleeve bearing is probably still available if needed, though this style was made to more than one set of dimensions. Not hard for any jobbing machine shop to make you one, anyway.

The half-coupling should NOT be free to move in any way on the shaft, if that is what is happening (I'm not totally clear whether that is what you meant. A little bit of 'backlash' in the gears is perfectly normal). If loose on the shaft, that is BAD and needs sorting properly before something fails. If the bore of the half-coupling has been worn by running loose, you might need to find an engineering shop to bore it out and sleeve it because the Lister type 6-bolt couplings aren't readily available (to my knowledge, but maybe somebody keeps them) off the shelf in the way the standard 4-bolt 4" flanges are.

To summarise, I reckon you need to strip the whole of your stern gear and clean it all up before making final decisions. You might decide you're better replacing the whole lot with modern 'standard' stuff with a weld-in boss for the sternpost.

Your present type has the advantage that the actual bearing is probably proper bearing bronze which can be replaced as a separate item, the current stuff flogged by the big chandlers has the bearing as part of the tube which may be made of some ill-defined brass/bronze material, quite possibly manganese bronze (propellor brass) which is not a 'real' bearing material.

Yours has the disadvantage of being held into the stern post by two bolts, this method can be troublesome if subjected to abuse such as clouting solid objects - including heavy ice - with the prop.

 

HTH

Tim

 

Hi Tim,

 

Thanks for that - a wealth of information!

 

I'm still trying to get my head around how this all works - is it a shaft log system, life the following pics?

 

 

 

If I'm understanding your info and how this is supposed to work, there's a sleeve bearing inside this tube, of the whole length of this 'log'?

 

Something like this:

 

 

 

Pictures blagged from random websites...

 

If so, why is mine bolted in place with the flange on the inside of the stern post, rather than outside as shown in the above pics?

 

I've not found a pic of the staking arrangement to stop the bearing turning yet, on the net anywhere - how does it actually go together?

 

Cheers again and sorry for the daft questions!

 

PC

 

Edited to remember to reply to this!

 

The half-coupling should NOT be free to move in any way on the shaft, if that is what is happening (I'm not totally clear whether that is what you meant. A little bit of 'backlash' in the gears is perfectly normal). If loose on the shaft, that is BAD and needs sorting properly before something fails. If the bore of the half-coupling has been worn by running loose, you might need to find an engineering shop to bore it out and sleeve it because the Lister type 6-bolt couplings aren't readily available (to my knowledge, but maybe somebody keeps them) off the shelf in the way the standard 4-bolt 4" flanges are.

 

The output flange from the reduction box can be rocked back and forth a few degrees without moving the actual prop shaft, so yes, it's loose on its shaft - I'm guessing it's ran loose and worn the keyway locating it in place...

 

Any thoughts on how knackered the reduction box is going to be, if the oil in it is black and sludgy? I'm still guessing that's from being sunk and water/oil/junk coming in via the output shaft seal... Reversing box is fine...

 

PC

Edited September 20, 2009 by paulcatchpole

[Phil Ambrose]

mild green hairy lip squid?

 

or is it only me that knows that joke?!

 

Reminded me of a gag we pulled on an American who worked wih us, on July 4th we presented him with a huge spanner (4ft long made of ply and painted silver) the spanner was wrapped in an enormous bra.

So he had "The bra bangled spanner" LOL well it made us chuckle in fact he took it back to The States with him when he returned home.

[Timleech]

If so, why is mine bolted in place with the flange on the inside of the stern post, rather than outside as shown in the above pics?

 

I've not found a pic of the staking arrangement to stop the bearing turning yet, on the net anywhere - how does it actually go together?

 

 

 

PC

 

Your first pic shows roughly how I would expect yours to appear from outside the boat. The other pics don't seem very relevant.

The sleeve bearing will exetend from the outer end of the tube, to just beyond the peg.

I don't understand your comment about the flange being on the inside, it looks from your original pic to be on the outside.

 

I'll see if I can dig out an old sleeve bearing and post a pic. later.

 

For your reduction gear, initially wash out all the sludge with paraffin or some such, then see how much free movement there is on the half-coupling both fore-and-aft, up & down, and rotational. There should be a little bit of the last, significant amounts of the other two indicate that more investigation is needed.

 

Tim

[MoominPapa]

If so, why is mine bolted in place with the flange on the inside of the stern post, rather than outside as shown in the above pics?

This:

 

 

would appear to look like you'd expect the other side of this:

 

 

to look if the retaining bolts went right through the hull and had nuts on the back.Is there not a flange visible on the outside?

 

MP.