Stubborn prop nut and more!

Ok...update

I went and measured the prop nut again to obtain the minimum reading I could across the flats and it came out as per the following picturesphoto-4.JPG
photo-3.JPG

1.379 inches and 34.8 mm

I also soaked the darn thing in plus gas, blocked the split pin channel one end and filled it and left it to soak.

I took a closer look at that thread and could just see the first coil by scraping away some gunk I hadn't seen in the twilight the other day.....the thread looks to coil away to the right, in a clockwise direction so I reckon it's anticlockwise to undo.

Tried a 36mm spanner which is obviously too big couldn't shift it but didn't try too hard. Will return to the fray in the week hopefully armed with correct size spanner!......and a blowtorch.....
 
Tim O said:
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!!!
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I doubt it applies to cows, but this is the method used to turn a two-week camel into four week camel ( in case you can't work it out .. sneak up behind while he's drinking .. clatter .. sharp intake of breath and lots of water).

Anyway, back on topic, avoid the lump hammer to avoid damaging whatever's at the other end of the shaft. LOTS of heat and a hub puller worked for me to remove the prop .. I would have thought the nut would be straightforward if you're trying to turn it the correct direction.
 
Big adjustable + 3 ft pipe to use as an extension for extra leverage.

If reasonable force does not shift it apply heat until it moves. A piece of sheet steel with a U shaped cut out can be used as a heat shield but if I was doing it I would not bother. If there is wind I might erect a tarp as a wind break. NB You need better than a wussy little propane torch, at least a gas axe is needed. Heat is your friend for this sort of job.

If you have to get the nut to red heat to undo it consider getting a new nut.
 
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TQA said:
Big adjustable + 3 ft pipe to use as an extension for extra leverage.

If reasonable force does not shift it apply heat until it moves. A piece of sheet steel with a U shaped cut out can be used as a heat shield but if I was doing it I would not bother. If there is wind I might erect a tarp as a wind break. NB You need better than a wussy little propane torch, at least a gas axe is needed. Heat is your friend for this sort of job.

If you have to get the nut to red heat to undo it consider getting a new nut.
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Heat is hus freind also can be hus enemy destroying tubber seals further up the drive.

I think we have keep to advice within practical lines, whats the prospects the o/p would have of access to an acetylene torch. If he has then all that transport hassle just for one nut? Why u said earlier remove the shaft and take it to a garage.

If he has access, he can go for it, meanwhile i have used a simple 'pussy' butane torch on many occasions to release nuts studs, stubborn brake drums etc, agreed it takes a little longer, but cheap and far easier to store between uses.

In my youth i owneda VW camper, could not shift the big nut holding the rear drum. I got it buy putting the van up on axle stands. Locking the other side with the handbrake adjustment.

Heated the nut up and positioned the 36" stilsons on the nut with handle against the road, and useing the engine to turn the shaft.

Being on my own it took several shots due to sliping, but it eventually did the job.

I'm of the same mind about the nut itself, if it takes a bit of a cosmetic beating far cheaper at this rate to replace it as required.

I've not noticed anyone mention how the shaft will be stopped from rotating while the forces of hell are being applied to turn this nut, is there some way to lock the shaft or will the o/p now need 2 sets of stilsons, 2 long tubes and another big bloke?

Alan
 
The "nut" might well have been loctited on .... perhaps even excessively so as I found with my prop nuts. I cut one off before realising that the excessive amount of loctite was the problem and I could easily resolve that with a little heat which even a small gas torch could provide. I reckon even a generous application of boiling water will provide enough heat to ease the loctite but 150 degrees from a torch would terminate it with extreme prejudice. :)

Richard
 
The use of heat does not need to be extreme it probably only needs a differential expansion between nut and shaft of half a thou. The nut expands more than the shaft!
 
Late to the party, but a couple of thoughts

After studying the pics closely, I reckon IMHO thats a left-hand thread. ie turn clockwise to undo.

If the OP is using heat on the nut, and if there is any danger of overheating stuff "up the line", it may surprise some to know that more heat applied for a shorter time will do far less danage. ie. use an oxy or propane torch counted in seconds. Wet rags applied to the shaft may help. Apply the flame directly to the nut only, and start turning before too much heat makes it to the shaft. Good luck!
 
Image1.jpg

As I said, just my opinion. Facing from the rear, the prop turns clockwise I think you'll agree, so most probably nut would turn ant-clockwise to tighten, and to me the photo appears to show the very ends of the threads. IMHO anyway.
 
Possibly someone in theYacht Club or the Club itself has an oxyacetylene torch....not that I'd know how to use one!

Will try all the suggested less drastic methods first and will double check what I can see of that thread.

I think this deserves taking a day off work to apply myself to this problem

I'm sure Special Leave would cover it???
 
Davegriff said:
View attachment 60572

As I said, just my opinion. Facing from the rear, the prop turns clockwise I think you'll agree, so most probably nut would turn ant-clockwise to tighten, and to me the photo appears to show the very ends of the threads. IMHO anyway.
Click to expand...

That's interesting .... I'd not looked closely at those later photos and was thinking you were forming your opinion from the ones in post #1. My mistake. :)

However, having looked at your highlighted photo I would draw the opposite conclusion and I think it shows anticlockwise to undo. Have another look perhaps?

Richard
 
Tim O said:
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!!!!
View attachment 60562View attachment 60563
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I,ve read the thread, and can only add by way of help that if the entire shaft could be withdrawn with prop attached, the lot brought to a engineer's would be better than destroying things.As I cannot see the photos for some reason, Perhaps this is bull*shit.Good Luck!
 
RichardS said:
That's interesting .... I'd not looked closely at those later photos and was thinking you were forming your opinion from the ones in post #1. My mistake. :)

However, having looked at your highlighted photo I would draw the opposite conclusion and I think it shows anticlockwise to undo. Have another look perhaps?

Richard
Click to expand...


And you may well be right! Opinion on here seems pretty divided. Maybe I'm biased 'cos I'd expect it to be left-handed, or perhaps I need new glasses? :D

Perhaps if the OP used a big magnifier lense and good light on the actual nut?
 
Good idea......i'm going to get down the boat for a good look first opportunity which unfortunately will be Wednesday now!!!

Hope you can all stand the suspense!

And would just like to thank everyone for all the contributions to this thread so far.......
 
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