Tips for removing flange off 45mm propshaft (replacing stuffing box with PSS seal)

vas

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21 Jun 2011
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Volos-Athens
afternoon all,

boat on the hard, one of v.few jobs I have to do is replace the traditional stuffing boxes with PSS dripless seals.
Steps taken:

undo the 4 10mm bolts from the flange holding propshaft
pull shaft back
undo the 38mm nut in the flange
since I don't have a suitable puller (will borrow one tomorrow but may not fit as I only have 160-180mm with shaft fully back and prop touching rudder)
I fitted a 30mm socket that fits the nut on the gbox side of the flange and pushed the shaft back and bolted them on again with longer bolts.
Tightened them A LOT and started heating the flange.
flange a serious piece of metal around 80mm in dia and another 80mm long before the actual 15mm thick flange which is 127mm wide.
with a blowtorch (small handheld with 400ml of juice and a 12mm orifice) I heated the lot uniformally for up to 10mins.
The theory has it that you tap it in the side and bang it comes loose.
yeah right, didn't, tightened with a 400mm lever on the 17mm socket the screws as much as I could, nada.
IR meter showed max of 150C on the metal body -shaft remained a cool 40-50C on the first couple of cm from the flange which is good. Thing is I'm not sure the IR goes over 150C got to check that!
Tapped again, ok, hit it with a hammer but not along the axle length as I don't want to force the thrust bearings on the box.

That's where I am now. Yes PO was in fond of hammers, whatever wasn't according to his idea he'd hammer it to death (same thing he did on the windlass drum!).
I guess he was trying to replace/tighten the stuffing box and he's scored the shaft a fair amount. Will see where that fits with the PSS and deal with it accordingly if needed.


I was generally v.kind with it and I'm afraid that's the problem .
So Q to ppl that have done that, how much heat am I meant to deliver? Get it up to red hot? if so my blow torch is not strong enough, got to get something larger tomorrow.
If I fail, I'll get a machinist to cut a suitable flange with the right holes to mount it, get it off the gbox and get a M16 or whatever large bolt/nut in the middle and stress it more before heating it again.

Any other tricks I may be missing?

cheers

V.
 

scottie

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scotland
two thoughts
1 Look again for locating screw in boss even if it’s a taper fit
2 leave under load overnight
 

vas

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21 Jun 2011
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Volos-Athens
scottie, can you explain #1 please?
shaft is tapered with one key visible on the flange - visibility is poor inside the flange, usually just take pics on my mobile and assess.
TBH, after removing the nut I didn't take a pic to see what's in there, maybe I should!

cheers
 

davidej

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17 Nov 2004
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West Mersea. north Essex
Good luck with this!

I spent a couple of days on a 25mm shaft coupling using a hydraulic puller , blow lamp, club hammer etc.

I ended up cutting the shaft, which was just as well as I found it was severely eroded in the cut less bearing area.
 

vas

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Joined
21 Jun 2011
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Volos-Athens
:eek: that's not the right post as I'm getting ready to go back and attack it again, is it 🤣

there are two of them, cutless bearing area is nice and clean, so really would v.much like to avoid having to go to such drastic solutions, not to mention the costs involved...
OTOH it's 20 or 40yrs old, which is some time stuck there...
 

kashurst

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Joined
10 Oct 2003
Messages
8,420
Location
west yorkshire
best puller you can find or make something with as big a bolt as possible in the middle. Get it as hot as possible then pour cold water on it. Repeat.
I helped get similar off a shaft - in the end the mechanic used a welding torch to get it REALLY hot! But we had been at it for three days and it was if it doesn't come off now we will have to cut it off. It did come off like a gun shot.
Best of luck.
 

Plum

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Joined
6 Jun 2001
Messages
2,878
Location
UK East Coast
afternoon all,

boat on the hard, one of v.few jobs I have to do is replace the traditional stuffing boxes with PSS dripless seals.
Steps taken:

undo the 4 10mm bolts from the flange holding propshaft
pull shaft back
undo the 38mm nut in the flange
since I don't have a suitable puller (will borrow one tomorrow but may not fit as I only have 160-180mm with shaft fully back and prop touching rudder)
I fitted a 30mm socket that fits the nut on the gbox side of the flange and pushed the shaft back and bolted them on again with longer bolts.
Tightened them A LOT and started heating the flange.
flange a serious piece of metal around 80mm in dia and another 80mm long before the actual 15mm thick flange which is 127mm wide.
with a blowtorch (small handheld with 400ml of juice and a 12mm orifice) I heated the lot uniformally for up to 10mins.
The theory has it that you tap it in the side and bang it comes loose.
yeah right, didn't, tightened with a 400mm lever on the 17mm socket the screws as much as I could, nada.
IR meter showed max of 150C on the metal body -shaft remained a cool 40-50C on the first couple of cm from the flange which is good. Thing is I'm not sure the IR goes over 150C got to check that!
Tapped again, ok, hit it with a hammer but not along the axle length as I don't want to force the thrust bearings on the box.

That's where I am now. Yes PO was in fond of hammers, whatever wasn't according to his idea he'd hammer it to death (same thing he did on the windlass drum!).
I guess he was trying to replace/tighten the stuffing box and he's scored the shaft a fair amount. Will see where that fits with the PSS and deal with it accordingly if needed.


I was generally v.kind with it and I'm afraid that's the problem .
So Q to ppl that have done that, how much heat am I meant to deliver? Get it up to red hot? if so my blow torch is not strong enough, got to get something larger tomorrow.
If I fail, I'll get a machinist to cut a suitable flange with the right holes to mount it, get it off the gbox and get a M16 or whatever large bolt/nut in the middle and stress it more before heating it again.

Any other tricks I may be missing?

cheers

V.
You are doing all the right things, sorry I can't add more, but if you are applying excessive heat while using the gearbox flange as part of your puller you run the risk if heat conduction to the gearbox shaft which may damage the oil seal in the gearbox. Better to use a dummy gearbox flange.

www.solocoastalsailing.co.uk
 

scottie

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14 Nov 2001
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4,592
Location
scotland
scottie, can you explain #1 please?
shaft is tapered with one key visible on the flange - visibility is poor inside the flange, usually just take pics on my mobile and assess.
TBH, after removing the nut I didn't take a pic to see what's in there, maybe I should!

cheers
Just check that there are no locating screws or pins on the body of the coupling the original fitter may have been a belt and braces guy could even be a taper pin filed over
it would be unnecessary of course but it’s a boat
 

vas

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Joined
21 Jun 2011
Messages
6,768
Location
Volos-Athens
Success! Came back, replaced a couple of bolts, tightened them A LOT evenly, got my torch back on it and within 10secs a great bang and it moved!
Mind it's not like it's loose wobbling about, tightening with some force two opposite bolts and has now moved around 14mm in total, can even see the key. Got to now undo the lot, fit a thicker spacer in there and start again. Wondering how I'm going to refit it now tbh!

Thanks for all the comments!
 

vas

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21 Jun 2011
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6,768
Location
Volos-Athens
Well, actually it was loose on the shaft except that key was stuck to the flange. Eventually all is out so got to clean sand and smear with a bit of oil the key before re assembly.

One more to go (on Tue got to have a break tomorrow...
 

burgundyben

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28 Nov 2002
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Niton Radio
Those half couplings with tapers are a right 'see you next Tuesday'.

New shafts snd R&D split half couplings is what you want.
 

vas

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21 Jun 2011
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Volos-Athens
oh, never seen these before BB, look v.expensive but very nicely engineered :cool:
not this year I'm afraid, See what else breaks before next lift-out in a couple of years time...

cheers

V.
 

vas

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blimey Trev! I'm exhausted just reading this PDF :eek:
glad that I have plenty of space to work on my e/r and that I only have one cutless bearing on the p-bracket which is fine.
Biggest pain for me was going up from the e/r, down the ladder to ground, push/pull shaft with prop, back up again check, back down again, repeat! that was after cleaning (but not polishing/lubricating!) the area in front of the p-bracket and before removing the old type seal. Now with PSS refitting it should be much smoother.
 

DrSpock

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31 Aug 2016
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Don't forget to check shaft alignment after you put it all back together.
 

vas

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21 Jun 2011
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6,768
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Volos-Athens
Don't forget to check shaft alignment after you put it all back together.
will do on the hard and then again in my mooring which is only 1km away.
Are the shafts reversible ?
? you mean turn it round and fit the prop on the now flange side?
No idea if the taper is the same and anyway wont be removing the props now . Mind if it is reversible, all the hammered bits are going to end on the p-bracket cutless bearing, not ideal
 

vas

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Joined
21 Jun 2011
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Volos-Athens
to close the thread, yesterday tackled the port shaft.
Same procedure, undo nuts, pull shaft back, undo 38mm nut, fit a socket, push back tighten HARD, heat A LOT.
heated it for a total of 15mins, tried the cool water trick wasn't impressed, so heated it again, tightened as much as I could the four bolts and went home
today arrived, all bolts loose, bang obvs happened during the night, I'm not complaining!
So job done, thanks for the info!

from this:

to this:

(above, just fitted not prestressed, have to pull the ss ring back around an inch)

cheers

V.
 

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