You have come up against the biggest, I think, problem with owning an alfetta. Some venders are selling a reproduction of the rear flex disc without the pilot bearing. not good. when a flex disc turns up which is correct it is usually OLD. better than nothing but rubber ages. I think this is what you have. I have managed to find a couple of NOS units for future but until someone remanufactures a correct rear disc, if ever, this achilles joint threatens the future viability of the car.