Prop Shaft Wear - Does this need replacing?

[macd]

I would of thought that when you heat a tube it's the material that expands, I would expect the outside diameter to increases and the inside diameter to reduce.

aren't boats fun

You'd expect wrong. Ever popped a main bearing into a motorcycle crankcase?

Yes, they're grand fun :ambivalence:

 

[fergie_mac66]

In it not possible to drill a hole through the skeg after putting new shaft skeg should be easy to repair

 

[Tim Good]

In it not possible to drill a hole through the skeg after putting new shaft skeg should be easy to repair

After drilling the hole, dropping the rudder, rehanging and then repairing I 'd have thought it would be the same amount of work as lifting the engine up.

 

[awol]

How easy to remove the P bracket?

 

[Tim Good]

How easy to remove the P bracket?

It's a Seastream 43. Built like a proverbial "%&*£@@$!

 

[fergie_mac66]

After drilling the hole, dropping the rudder, rehanging and then repairing I 'd have thought it would be the same amount of work as lifting the engine up.

Well it seems to me that if a properly job is done of the hole and the skeg is strengthens and the hole caps are put in if there is ever another problem then a future problem could be fixed quickly , admitted, unlikely but long term sensible

 

[Iliade]

Dropping a tube over the worn area is not a daft idea. The easiest way would be to buy a split coupling* long enough to give a reasonable contact area either side of the worn region. If there's room...

* http://www.techdrives.co.uk/shaft-rigid-joints.html

However, without labour, it may be cheaper to undo the engine mounts, slide the shaft back and fit a new one.

Edit: if there's not enough meat for the coupling, there may be enough room to cut out the bulk of the worn area, bring the two ends together and bob's a close family relative.

 

[Neil_Y]

Considering shaft area, torque and possible corossion I'd be looking for a new shaft.

Talk to Timken (and a stern gear supplier like Clements) about the torque rating for couplings but I see no reason not to use something like this

If the picture of the P bracket shows the shaft in its normal position you could loose an inch there.

 

[vyv_cox]

Considering shaft area, torque and possible corossion I'd be looking for a new shaft.

Talk to Timken (and a stern gear supplier like Clements) about the torque rating for couplings but I see no reason not to use something like this
......
If the picture of the P bracket shows the shaft in its normal position you could loose an inch there.

The coupling photos show a keyway. Fitting them would require the shaft to be cut, machined with two matching keyways, plus the cost of the coupling. I suspect that a new shaft would be cheaper and a lot more convenient.

 

[Tim Good]

The coupling photos show a keyway. Fitting them would require the shaft to be cut, machined with two matching keyways, plus the cost of the coupling. I suspect that a new shaft would be cheaper and a lot more convenient.

Cost of shaft doesn't phase me. £350 from Norris. I am just sweating as I have 6 weeks before the boat goes in prop or not. And Portishead doesn't exactly have a huge qty of marine engineers with time to start lifting engines to slide it out forward. Maybe if I get swimbo to bake cookies it might speed things up.

 

[ribrage]

Cost of shaft doesn't phase me. £350 from Norris. I am just sweating as I have 6 weeks before the boat goes in prop or not. And Portishead doesn't exactly have a huge qty of marine engineers with time to start lifting engines to slide it out forward. Maybe if I get swimbo to bake cookies it might speed things up.

Sounds like a trip up the river and a chat with David Ables on spike island might be required ??

 

[Tim Good]

David Ables on spike island might be required ??

Who might that be? I found his website and it says "Architectural Sculptures". Is he renowned for good work or something?