apologies to rustyc and others for my parochial comments against the term prop shaft. Seeing a post from the exotic Canary Islands, I rashly presumed a fellow sailor was simply applying nautical expressions to non-nautical items, as I am wont to do myself. My steering wheel is the helm and my doors are hatches, but I have not yet figured out what to call the brakes.

anyway, sounds like wiser counsel has arrived, so I shall sit back and keep quiet!

 

Gearbox mount, the one you have to jammy bar out the way to move the gearbox back away from the engine is knackered.
And the noise has vanished all of it's own accord. fabulous.
Thanks so much guys.