Prop shaft flange removal

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blackfish

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Help reqired please. I'm trying to remove the coupling flange at the inboard end of my propshaft. The end of the shaft itself has a thread with a nut and washer, which has been removed. However, I cannot get the cast metal flange to budge at all. I've tried gentle heat and tapping and also a 'hub puller' but to no avail. I'm assuming that the casting is prevented from rotating by either a keyway or a spline. I cannot see any kind of grubscrew so I'm assuming that it's just a matter of brute force. Any suggestions please?
 
If it is on a keyway the shaft is probably tapered. You can check by measuring the diameter of the nut compared with the shaft. If it has been on there a long time it may well take a lot to shift it. Assume the shaft is out of the boat, in which case stand it upright and fill with penetrating oil. Apply heat and a puller and eventually it will come. (Double check there is not a pin or grub screw first)
 
Just removed mine. It was held on a taper with a key, with locknut and washer within recess at forward end.
Removed it using a hub puller. Applied tension, then hit it with lump hammer. It came off a treat.
 
A taper pin, roll pin or grub screw should be pretty obvious, so I assume you have none of these. If you look closely at the end of the flange beneath the washer you should be able to see whether there is a keyway or not. One possibility, although I have never seen one on a yacht, is that the flange itself is threaded, again this should be obvious by inspection.

Once you have satisfied yourself that it needs a straight pull to get it off I can recommend the method proposed in the other thread. Put a large nut or some other suitable metal lump between the shaft end and the gearbox coupling. Refit the coupling bolts and tighten them progressively. I have found this to be far more effective than a puller.
 
Thanks for the suggestions. The shaft is still in the boat, so difficult to see clearly. I understand grub screw, but, forgive ignorance, taper pin and roll pin are new terms to me. What I can see with the nut and washer removed is one small notch in the recess which surrounds the end of the shaft (looking at it end-on). Does anyone know what this might be and if it is a component which needs to be removed, how?
 
A grub screw and a roll-pin would both go through the coupling and into the shaft at 90degrees. A roll pin is just a small tube that was been sawn down the length on one side and is spring steel and knocked into the hole much like a grub screw is screwed in. The purpose is to stop the shaft sliding out of the coupling. As yours has a nut on the end then that fulfils this purpose and there possibly is no other fixing. The notch is probably a keyway and shouldn't stop the shaft coming out. Try some of the methods to free the coupling from the shaft that are suggested in the other thread - I expect that it is just stuck in there and you need to break the seal between the cast iron coupling and the SS shaft.
 
Description of a taper pin here A roll or spring pin is tubular made from spring steel and is used in a parallel hole which rather than being reamed to size is frequently just drilled. They are both used to locate and lock things together.

A taper or roll pin is unlikely as MoodySabre says it would be surplus to requirements but they can be filed flush with the surface to prevent accidents and painted over to cause frustration. /forums/images/graemlins/smile.gif
 
Notch equals keyway, if it had a nut on the end it is not a parallel keyway therefore it will be a tapered shaft, therefore it will be a tight fit NOT a grub screw or roll pin. Tighten puller or put a plate on the end and tension it, then give it a sharp blow on the end of the puller or the plate, it will jump off as described in the other posts.
Stu
 
Thanks to all for suggestions. Tomorrow I'll try the spacer on the end of the shaft method, by tightening the coupling bolts up on it. One thought - is there any danger of damage at the gearbox side by using this method?
 
Success! Thanks to all for advice. Putting a spacer between the shaft end and re-tightening the coupling bolts did the trick. Just for interest, it is indeed a tapered shaft with a keyway.
 
I learned very early on in my mechanical engineering life that there are only so many ways of doing "something" and alittle bit of inspection combined with the "knowledge" usually gives the right answer!
Stu
 
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