Shaft Coupling Removal

[Stoshak]

I need to replace the Volvo shaft seal on my boat, 25mm propshaft and Yanmar 2GM20F.

The shaft coupling is solid ie not split halves. I can see the groove for a key in the aft face for torque transmission, but I can't understand how the shaft is held in the coupling longitudinally. No radial grubscrew for instance.

Is there likely to be a taper somewhere?

I'm drying out next week to do the job, and don't want any unpleasant surprises!

 

[lw395]

Could be a nut on the engine side of the coupling? Probably as you say, a tapered shaft. You may need a puller to remove it.
The key is really only to help doing the nut up, its the taper that transmits the torque.
Good luck!

 

[alan006]

You might find that the end of the shaft you can't see ( hidden by the flange) has a thread on it and there is a nut holding the shaft to the flange.
Hope this helps.

 

[damo]

Mine is a similar setup, but with a high tensile bolt through the lot. Give the surface a good clean and see if there is a pin through it - the ends may have been peened and made flush, or filled with rust etc.

Is the exposed end of the shaft the same diam as the rest?

Whatever the situation it will probably need severe heat and a press to shift it /forums/images/graemlins/frown.gif

 

[beneteau_305_553]

The standard coupling has 4 cap head bolts that clamp the coupling to the shaft. Slacken these off and the shaft should slide away from the coupling. (You may need to tap the coupling to get the shaft to release ).

 

[Stoshak]

Removed it today, took a bit of shifting but not too bad.
It is indeed a taper with a large self locking nut on the end of the shaft. Loctited on so not easy to undo!

Thanks for the advice.