Stubborn prop nut and more!

Tim O

Tim O

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Ok.....attempting to remove my prop.

Of course, this being a boat the prop nut does NOT want to come off.

Firstly as you can see from the photo it's a speciallly made nut with only two flats and a hole through nut and shaft to accept cotter pin.
The distance across the flats measured with a digital calliper is 35mm or 1.4 inches which I think translates to 1 3/8".

So, I'm assuming I need an open ended spanner marked 1 3/8".....correct?

I only had a big adjustable spanner and I used a two foot length of scaffold pole over it but because of the play in the adjustable spanner it was beginning to slip and potentially round of the nut "corners"

So....my plan is..buy a proper fitting open end spanner, and use the scaffold pole...if thst doesn't work try whacking the spanner with a lump hammer, if that doesn't work try heating it up then follow same sequence.

How much heat is ok to apply? It's tight up against the prop....any danger of overheating that?

I'm assuming a prop nut will be normal thread... anticlockwise to undo??? I tried other way too....nothing budged!!!!
photo-2.jpgphoto.jpg
 
Btw, I am aware stuck nut issues are old hat and probably make some of you groan and say "not again".....but any help most appreciated!
 
You will have to rotate it the same way as the props rotate,when going ahead,to get it off (normally).

I had an MG TC with knock off hubs (1948 vintage) same issue ,

See you are single screw but if you were twin engined they would probably be contra rotating ,so clockwise and anticlockwise.
 
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I have no dealings with this issue, but if faced with it no way use an adjustable spanner. If anything use what a called pipe workers stilt-suns (not sure of spelling), as you apply pressure the design auto closes the jaws like a ratchet to reduce slipping and you should be able to hire them., but they won't appreciate being hit with a club hammer, being made of a hard brittle steel, that can be easily shattered.

I'd try to get that proper adapter. and would favour heating up the nutt then using a compressed air driven impact gun, (as used in tyre centres).

Alan
 
Mad Pad said:
You will have to rotate it the same way as the props rotate,when going ahead,to get it off (normally).
Click to expand...

Well the prop in the photo is a righthand / clockwise prop so that would suggest the nut has to be rotated clockwise to loosen it. I don't know whether the rule has 100% applicability but if so the OP has been mainly trying to turn it the wrong way.

Richard
 
Yes,but you have to know which way to turn it..see my previous post.

It's called a stilson ,I have one on board about 3' long which will shift anything or turn the propshaft into a corkscrew.
 
RichardS said:
How would you use an impact gun on a non-standard "nut" like that? :confused:

Richard
Click to expand...

As I said, I have had no dealings with props or their removal, I would hope the adapter (being an adapter) would fit a standard 1/2" drive. If all else failed it weld it to a 1/2" short extension rod.

I've used a 12 volt impact gun version to remove a flywheel on a 500cc scooter, official way was to use several types of fairly expensive tools. This gun was bought by the wife, laid idle for several years out of my shear disrespect already having a compressor and air impact gun.

When I started on the job my compressor failed, begrudgingly I used this cheap nasty looking tool. It did the job 1st try.

Sometimes you just need to try trying something new �� .

Alan
 
RichardS said:
Well the prop in the photo is a righthand / clockwise prop so that would suggest the nut has to be rotated clockwise to loosen it. I don't know whether the rule has 100% applicability but if so the OP has been mainly trying to turn it the wrong way.

Richard
Click to expand...

This seems to be a fairly critical part of the puzzle!!!! Any further views on this?
 
I would have thought a careful inspection of the exposed end of the shaft would identify whether it is normal or clockwise thread. After that I'd certainly try some heat on it and probably a damn good whack, end on, with a club hammer to hopefully break free any corrosion deposits which might be restricting its movement.
 
Tim O said:
This seems to be a fairly critical part of the puzzle!!!! Any further views on this?
Click to expand...

From what I have seen on outboards, there is often a portion of exposed thread, either the shaft is long enbough to protrude, of thread seen through a slot.

If below the nut getting a bolt the same diam might thread in, or not according to the 'hand'.

Regards the adapter, Metric is a relatively new option in spanner world, if the shaft is old, perhaps made in America as example, it could be AF, BSF American Fine or other.

ALAN
 
Keith-i said:
I would have thought a careful inspection of the exposed end of the shaft would identify whether it is normal or clockwise thread. After that I'd certainly try some heat on it and probably a damn good whack, end on, with a club hammer to hopefully break free any corrosion deposits which might be restricting its movement.
Click to expand...

TBH, I would not ever directly whack the shaft end on with a hammer, way to much risk of mushrooming the shaft (like happens to cold chisels), and also damaging a bearing, seal or mount further down.

Alan
 
There is no thread visible unfortunately......tried that!!!

It has been suggested whacking nut from both sides with two hammers to avoid transmitting force lengthways up the shaft.....in the manner of castrating a cow with two bricks! (Probably an urban myth but you get the picture!!!
 
Pretty sure it is irrelevant which way the prop rotates. No way can the nut come off when the shaft is turning as the prop is on a taper with a key and the nut is pinned to the shaft. It will be normal anti clockwise to undo.
 
Check with someone like TE Norris if this is a standard type of prop nut ? If you can buy a new one - easier to grind it part through, weaken it and whack it off.
Whatever the thread is on there - one will be able to get a new nut to suit - I would have thought.
 
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