Repairing a flexible coupling

[Arthur Marshall]

My somewhat ancient Lister has a fifty year old coupling, which is about four times the size of modern ones, probably about ten inch in diameter and with about a three inch thick chunk of rubber in the middle.. To get the gearbox out and to undo the coupling we had to saw chunks of the rubber out to get at the bolt heads which were slipping when we tried to undo the nuts. It's still got a fair bit of rubber in it but any ideas as to what i could use to fill the chunks that have been sawn out, as much as to make it keep in balance with itself as much as anything else. Or doesn't it matter?

[bizzard]

My somewhat ancient Lister has a fifty year old coupling, which is about four times the size of modern ones, probably about ten inch in diameter and with about a three inch thick chunk of rubber in the middle.. To get the gearbox out and to undo the coupling we had to saw chunks of the rubber out to get at the bolt heads which were slipping when we tried to undo the nuts. It's still got a fair bit of rubber in it but any ideas as to what i could use to fill the chunks that have been sawn out, as much as to make it keep in balance with itself as much as anything else. Or doesn't it matter?

This, I think is that type is the original one. Lister one, like a small thick tyre clamped either side by its beads by grooved plates, if so there should be a plummer thrust block between it and the stern tube. They are a very good flexible joint. They can be replaced by the Ford Granada prop shaft rubber doughnut cheaply. The holes of which align exactly with the Lister half coupling bolt holes. Three bolts one way and three bolts the other, with washers as spacers to give fore and aft flexible clearance.

[Arthur Marshall]

This, I think is that type is the original one. Lister one, like a small thick tyre clamped either side by its beads by grooved plates, if so there should be a plummer thrust block between it and the stern tube. They are a very good flexible joint. They can be replaced by the Ford Granada prop shaft rubber doughnut cheaply. The holes of which align exactly with the Lister half coupling bolt holes. Three bolts one way and three bolts the other, with washers as spacers to give fore and aft flexible clearance.

Not sure - this is it:

Mine's got five bolt's holding it to the Lister half coupling - the Ford one seems to have three?

Edited December 8, 2016 by Arthur Marshall

[bizzard]

Not sure - this is it:coupling.jpg

No, that is not the type I speak of. The damage could I suppose be filled with some black silicone or the rubbery battery case repair stuff.

[FadeToScarlet]

Not sure - this is it: coupling.jpg

Mine's got five bolt's holding it to the Lister half coupling - the Ford one seems to have three?

I have one the same, or remarkably similar.

 

And a Centaflex- the poor man's Aquadrive!

[bizzard]

The standard output half coupling on the back of a Lister LM100 or LH150 or the reduction box is 6 bolts.

[blackrose]

Could try this,:

 

http://www.toolstation.com/shop/Adhesives+%26+Sealants/d180/Grab+Adhesive/sd3199/Stixall+Adhesive+%26+Sealant+290ml/p60981

 

Goes off like rubber, much better than soft silicone. But you'll have to degrease the bonding surfaces first with some white spirit.

[Arthur Marshall]

Thanks - I'll try some of that.

In addition, the guy who replaced it seems to have got a couple of the bolts in the wrong place and one appears to be missing at each end. How critical this is I don't know but must confess it worries me a bit. Ran the boat for a few miles this morning and it seems OK but the thing's been hacked about so much that I reckon it may well be time to replace it with something more modern. Do these couplings have a use life or do they just go on till you hit something? This one must be about fifty years old.

[blackrose]

Thanks - I'll try some of that.

In addition, the guy who replaced it seems to have got a couple of the bolts in the wrong place and one appears to be missing at each end. How critical this is I don't know but must confess it worries me a bit. Ran the boat for a few miles this morning and it seems OK but the thing's been hacked about so much that I reckon it may well be time to replace it with something more modern. Do these couplings have a use life or do they just go on till you hit something? This one must be about fifty years old.

I think I'd probably be looking around for a suitable replacement.

[J R ALSOP]

I thought the Python was the poor man's Aqua Drive.