Propeller removal - any ideas?

[LeonF]

I'm no mechanic, and had great probs trying to get my prop off it's tapered shaft a while back. All the sailing club wags gave it a go using a variety of methods, but admitted defeat. The yard who had last put it back on after changing the cutlass bearing happened to be working nearby. I gave them a call and told them it had been suggested that I had a bent shaft. With a hydraulic puller it came off first time.

 

[anderson]

prop off

screw the nut nearly fully on hit the end of the shaft, the shaft will then jump through the prop by a few thou it should then be loose.,

 

[NormanS]

screw the nut nearly fully on hit the end of the shaft, the shaft will then jump through the prop by a few thou it should then be loose.,

And then as Vyv Cox says "Then take the gearbox out to replace the output shaft bearing!

 

[alan17]

If only. When I wanted one to pull a bearing off a gearbox shaft all the local garage could offer was to fit a new/recon gear box!
(actually got it pulled off and a new bearing pressed on by a gearbox "reconditioners" in the end ... but any small garage ... nope)

Well they damn well should have. Clearly you frequent the bodgers and there are many of them. I am a self employed motor mechanic. No employees other than me and I have the said hydraulic puller and bearing separator. Those that do not have this equipment should not be in business. Without this kit damage will frequently be done. It pays to buy the right tools for the job.

 

[Poignard]

This type is easy to make and it works reliably even when your propeller boss has been mauled by hammer wielders.

There was a photo attached to this when I posted but now it's gone! Can't trust anyone these days.

 

[boggybrn]

Propeller removal - happy ending

The propeller is off!

Thanks to Dunmor for the idea of using tow bar drop plates, I made a custom puller.

With this in place it was simply a matter of tightening each bolt in turn, until after a little creaking... BANG! Job done.

I was even able to remove the cutless bearing quite easly, by removing a single grub screw and pushing it out by sliding a bit of split copper pipe down the stern tube.

As for the thread on the bolts - well I just bought 3 M12 bolts without even looking at the pitch of the thread. None of them broke, so they must have been strong enough!

 

[Ubergeekian]

The propeller is off!

Thanks to Dunmor for the idea of using tow bar drop plates, I made a custom puller.

With this in place it was simply a matter of tightening each bolt in turn, until after a little creaking... BANG! Job done.

Congratulations!

To all the other excellent suggestions I was going to add one more ... time. It's often surprisingly effective to fit a puller, tighten it up and then just leave it. Check every now and again and tighten it up if it's released at all and nornally, after a while, you'll get the BANG. It might be a matter of hours or even days. A friend of mine had a hydraulic puller straining at its seams for two days on a Triumph Vitesse rear hub. He was indoors having his lunch when he heard the BANG! - the puller and hub had shot around ten feet from the end of the driveshaft!

 

[maxi]

Prop puller

I have a home made prop puller of the type under dicussion &, I am not a million miles away from Fareham.

If you want me to have a try with you, drop me a post with a phone number and we might be in business.

 

[Bosun Higgs]

The trick of hitting with hammers both sides of a seized fitting at the same time works very well with rusted on mooring shackles. Never yet failed to free one off, however old, by this method. And of course heat wont work in this case.

For a bronze prop on a steel shaft, heat is the kindest way if you can get the shaft out complete with prop. I can but it was necessary to leave the blowlamp heating up the prop for 5 mins or more to get it warm enough, but then it was only a small domestic lamp.

 

[AquapartPhil]

RUBBISH.

Ive Worked In Engeerneering All My Life,! And I Do Know What Im Talking About!!!
Look At The Thread On Any Good Puller & it Will Have A Coarse Thread.[/QUOTE]

Correct !! Any Engineer or Toolmaker knows that a coarse thread is stronger than a fine one, however the apex to root weakness problem is compounded on a fine thread as they have a greater mechanical advantage over a coarse one so for any given load on the spanner a fine thread exerts a much greater linear force and will strip much easier.
Although most pullers have coarse threads, I have seen some pullers with fairly fine threads however they are usually made from some exotic hardened steel.
As far as the prop goes I would go with Oxy-Aceteline and a clout (on the side) of the hub in all 3 root areas.
Another often overlooked technique on siezed shafts, studs, pins etc is to apply intense heat to the pin/stud/shaft etc allowing it to expand and stretch the surrounding hub/casting/nut/ slightly, then allow it to cool off when it then shrinks back and often becomes free (hopefully)

Phil