ok, so on to the next job!
While I was under the car, I noticed that the "rear propshaft rubber coupling" (i think this is known as the donut/doughnut) was slightly perished.
It looked generally ok, but there were a couple of cracks in it, maybe 3mm deep or so.
Also, I noticed that where the rear propshaft enters the rear diff, there was a slight oil leak. Nothing major, but may as well sort it at the same time.
So... regarding the "rear propshaft rubber coupling", it's the rubber thing with 6 holes in it, which appears to transmit drive to the rear diff from the prop shaft.
God knows why the entire weight of the vehicle, with potentially 3 tonnes of caravan behind it, on a steep hill combined with the power of your foot to the floor trying to pull away should be transmitted through a single piece of rubber... seems like a really bad design choice, but i'm sure there's a reason. Someone please tell me if there is!
Secondly, is this really the thing known as a donut/doughnut?
Thirdly, how bad does this have to be to warrant replacing it?
Fourthly, would you say it was a safety-related item? Surely the worst that should happen if it fails is me dragging the prop shaft along behind me, with it still attached at the front, right?