G'day Mick
My prop shaft failed from long term fatigue due to bad alignment. I replaced it while the boat was in the pen. It sounds like the thread on yours is probably stripped and the shaft will need replacing.
I also thought I would have to drop the rudder to get the prop off and shaft out. I thought of just tying lots of rope to the rudder in various ways so that I could just drop it literally to the bottom and haul it back up later but found an easier way.
Before I started this project I went to be Coles self checkout and asked for about 30 shopping bags...
First thing was to tie rope around prop and tie off to the boat so you don't lose it. take off the prop nut and slide prop back till it touches the rudder and just about to drop off shaft.With a large piece of wood across the companion way, I used the main sheet block and tackle attached to the lifting ring on the engine, I uncoupled the prop shaft, undid the engine mounts and lifted the engine enough ( about 4-5 inches) to slide the prop shaft forward. You need someone in the water as you do this. the prop will hang on the rope as the shaft slides forward and as it does, stuff in the shopping bags. About 2-3 for now will completely stop the water. Pull the shaft out completely and stuff bags in from the inside till it stops dripping. They work so well. I then dropped the engine back on its mounts and stuffed about 4-5 more bags in to make sure.
Just did the reverse with the new shaft. Got the alignment perfect and I swear no more than a litre of water in the boat. I relied on the bags for the 3 days it took to turn the shaft for me.
Put the collar back on the new shaft in the same place as the old. Don't even worry about taking all the bags out when you put the new shaft in just in case you get stalled. Leave the original 1-2 in the tube as backup. Just push the new shaft in until the collar touches the prop shaft seal. The bags will push out the back. Have someone catch them as they do. Put on the new prop, tighten and pin the nut.
Whole job, $250 for the new shaft cos Coles gave me the bags!
Don't forget to take the prop in to get taper right.
Cheers

ps all this 3 days before Christmas so it was shopping bags or no sailing until march when I could be lifted out...

manitulak said..
Hi Moocher, if your prop got tapper with keyway, sorry I got bad newsfor you. In best case prop retracting from tapper (I doo belive 1 to16) will only engage prop "grove" at 50%, damaging the sides of the prop "grove". On the good side, more damage will be on prop than shaft. Lets hope new shaft will not be neccecary. From my experience tappered joints with "holding"nuts without keyway are suffitient, keyways are needed in rapid changes of temperature and for those skippers who ignore 1.2.3. seconds betwin forward and astern. All The Best.

Manitulak . His prop did not fail nor his prop tapper on the shaft , the way I read it. Moorcher had a different problem misalignment
But I like moochers improvisation Ill keep that one in the back of my head

HG02 said..

manitulak said..
Hi Moocher, if your prop got tapper with keyway, sorry I got bad newsfor you. In best case prop retracting from tapper (I doo belive 1 to16) will only engage prop "grove" at 50%, damaging the sides of the prop "grove". On the good side, more damage will be on prop than shaft. Lets hope new shaft will not be neccecary. From my experience tappered joints with "holding"nuts without keyway are suffitient, keyways are needed in rapid changes of temperature and for those skippers who ignore 1.2.3. seconds betwin forward and astern. All The Best.

Manitulak . His prop did not fail nor his prop tapper on the shaft , the way I read it. Moorcher had a different problem misalignment
But I like moochers improvisation Ill keep that one in the back of my head

Hi HGO2, yes you are right, his prop did not fail, just wobble remining on the shaft (I read it and took into account) With 6 to 10 mm play of the prop on tapered shaft it is not misaligment, it is ...... (My spell check does not allowing it), let say baddddd. Nobody in todays world is using paraller shaft/prop with grub screws connection, and if some doo, they are used to the custom of thighening them every time boat is on trailer.
Just theory, if hee only use farward/ahead revolution direction prop will stay at its designed place seating on full taper, but if hee reversed/go astern prop would come off its taper resting on the nut and in this moment keyway key is the only means to prevent free spining, but keyway key is only partialy engaged with shaft and/or prop, so something will work "overtime" lets hope it was his old bronse prop which was beaten out of shape, not the keyway key or shaft grove. Are we at home? All The Best.

HG02 said..

manitulak said..
Hi Moocher, if your prop got tapper with keyway, sorry I got bad newsfor you. In best case prop retracting from tapper (I doo belive 1 to16) will only engage prop "grove" at 50%, damaging the sides of the prop "grove". On the good side, more damage will be on prop than shaft. Lets hope new shaft will not be neccecary. From my experience tappered joints with "holding"nuts without keyway are suffitient, keyways are needed in rapid changes of temperature and for those skippers who ignore 1.2.3. seconds betwin forward and astern. All The Best.

Manitulak . His prop did not fail nor his prop tapper on the shaft , the way I read it. Moorcher had a different problem misalignment
But I like moochers improvisation Ill keep that one in the back of my head

Thanks everyone for your input, your right Manitulak there is a taper and that's why I thought if I can tighten the nut it would push the prop back up on the taper and that should keep it in place, we had to use a puller to get the thing off. My 'enthusiastic' mate, he liked that description, came over to discuss the problem and we're both at a loss as to how this has happened. The shame of all this is the shaft was replaced by Porter's 4yrs ago after I surveyed the boat.

oldboyracer said..
you don't mention the size of your boat , I recently slipped mine and did some work at endeavour marine at Botany Bay , pleasant sail down , they have 2 slips and a work berth , although you can't use the work berth from Friday morning till Monday as the sailing club use it . I found them very helpful When I was there .

The boat is 46ft which because of it's larger size is understandably more expensive, however, since Riverside Quays sold out there are only two Hardstands in Sydney Harbour where you can do your own work and they're both owned by the same bloke, so name your own price??? Do you think Endeavor can lift approx 12tonne. Someone mentioned there's one somewhere in Port Stephens. Thanks again I appreciate the input.

It often pays to fit the prop first without the key, tighten it up and measure or reference mark how far on the shaft the prop seats. I also do this with bearing blue to indicate the fit on the taper is correct. Then remove it and fit it back on with the key in place and make sure the prop seats to the same position. If it dosen't it is most likely riding on the key and incorrectly fitting. Again, the use of bearing blue will indicate the fit of the key.

jolene,s way of fitting a prop is the correct way to do it
takes out all the guess work out of it cheers ray