How to remove propellor shaft from coupling?

[pampas]

check to see if the pin is a smaller diameter at one end if so its a taper pin. in any case beg borrow steal or buy a pin punch ( Easily obtained from a motor factor or tool shop) small end up shaft coupling blocked drive pin out with a heavy hammer.
Slide shaft back further and hire a three legged puller, you might have to remove rudder or turn to max hard over to get enough room for puller. Hopefully it may not be too tight some heat from a paint stripper gun would be useful.
Best of luck.

 

[PuffTheMagicDragon]

That does look exactly like the gearbox fitted to my VP MD2B.

I thought it would be!

The one in my photo is from the MD2B that is on my boat, built in 1973.

 

[parbuckle]

The so called pin appears to be more than 6mm dia quite large and more likely to be the head of a set screw , I would clean it up with rust solvent or scraper first to be absolutely sure also there appears to be a woodruff key or maybe a guide so the hole can be relocated when refitting as it would be very difficult to reposition . If it is a pin can you see the other end as it must go right through.

 

[Jokani]

Thanks Pampas, I just bought a 3 legged puller to puller to remove the prop, never thought of using it for this. Seems a safer option than bolting back up the flange with a socket space.

I hope to take a day off on Thursday and go to the boat. Will report back then, it will be interesting to see whether a pin or a screw.

 

[vyv_cox]

It seems to me that I can see a rust-filled slot in the top of the 'pin' in your photo, which might correspond with the setscrew described in your post#10.

 

[scottie]

Taper pin better engineering answer

 

[david_bagshaw]

Is there room to lift the engine and draw the shaft inside?

 

[Jokani]

Unfortunately not, I would need to remove the engine completely, I'm tempted to say that would be far more hassle than its worth, but I'll see how the other options go first.

 

[Heckler]

Unfortunately not, I would need to remove the engine completely, I'm tempted to say that would be far more hassle than its worth, but I'll see how the other options go first.

You will find that after a good cleaning around it, figuring out what is actually holding it then it will be a relatively easy matter to get the thing off
Stu

 

[Jokani]

A quick update. I cleaned out both the large and the small holes. Both were just smooth surfaces so I presume it is a taper pin:

I supported the shaft with some 4" x 2", after leaving to soak in Plusgas I hit the small end as as hard as I though reasonable, without success :-(

I'll try again at the weekend and heat the coupling with a blowtorch and take a larger hammer.

I have also tried to source a new coupling should I need to cut it off, but so far have been unable to find one, so that may not be an option either.

 

[GrahamM376]

A quick update. I cleaned out both the large and the small holes. Both were just smooth surfaces so I presume it is a taper pin:

I supported the shaft with some 4" x 2", after leaving to soak in Plusgas I hit the small end as as hard as I though reasonable, without success :-(

I'll try again at the weekend and heat the coupling with a blowtorch and take a larger hammer.

I have also tried to source a new coupling should I need to cut it off, but so far have been unable to find one, so that may not be an option either.

The wood support you are using may absorb much of the shock of hitting the pin, better with steel. Plenty of new couplings here, split are best - http://www.randdmarine.com/sshcouplings.asp

EDIT - put the support under the coupling, not the shaft.

 

[Ruffles]

I'll try again at the weekend and heat the coupling with a blowtorch and take a larger hammer.

Suggest the head of a sledgehammer would be a better anvil.
Also when using a blowtorch near the hull use plasterboard as a heat shield. Or alternatively softwood soaked in a bucket of water for a few days.

 

[Jokani]

Thanks for the ideas.

Suggest the head of a sledgehammer would be a better anvil.

I'll try that

Also when using a blowtorch near the hull use plasterboard as a heat shield. Or alternatively softwood soaked in a bucket of water for a few days.

I have an old fire blanket I think I can use for that

 

[Billjratt]

I have a bit of experience with taper pins. Tabulaters (computers to you,) were held together by them.
The trick is NOT to be timid when removing them. If you tap away, you will only bell the thin end or bend the pin and it will never come out.
Looking at your pix, I would put a 2-1/2lb mel under the coupling but clear of the large end of the pin, as an anvil.
Then make up a punch with a parallel section the same diameter as the small end of the pin. (just grind the nose of one of your centre punches for about an inch.)
ONE good smack with a 2lb hammer should shock the pin free.
What happens after that will depend on corrosion - If neccessary get a stout metal plate, drill it to match the flange holes and use it with long bolts and a suitable spacer to press out the shaft.
Don't use sandpaper on the coupling or shaft when you get it out. Just clean it back to the original surfaces or it will be too loose a fit. If you can't get a new taper pin you can redrill the hole parallel and fit a roll pin. There are taper reamers available to set the new pin if you get one (the new one will be longer -just trim it once it's been driven home.)

 

[ghostlymoron]

When you do get it off, I would replace it with a split type.

 

[fisherman]

When you do get it off, I would replace it with a split type.

If you're going to replace it, just as well cut it with an angle grinder. Split couplings on the shelf http://www.candoengineering.co.uk/

 

[Neil_Y]

ACF-50 is a far better agent for freeing seized parts than +gas or WD.

 

[Jokani]

Update - Job over - Took hours of cutting. Even when half was off and the taper pin revealed, the remainder wouldn't free itself:

Had to make more cuts, but eventually:

It will take a good few hours to clean up, but new spilt coupling on its way so hopefully back up and running with a new PSS seal shortly.

Thanks for all the help and advice.

 

[GrahamM376]

Well done, many people would have paid to have that job done for them.

 

[chrishelen]

Well done, those pins can be a nightmare to remove, apart from rusting in they distort slightly and banging them just bends them a bit more, I used to drill them out.