I recently had an issue with the rubber doughnut on the prop and I got it replaced with one from ebay (just the doughnut). The two viscous coupling baerings were replaced at the same time. The rear bearing failed about 2000 miles later. I thought it may have been a failty part so it was replaced again and it has failed within 1000 miles. There is obviously an underling issue. The prop is bumping on the bottom of the car but only when you are turning left or right at slow speed. The rear bearing has collaspsed. Is it likely to be the viscous coupling?

probably too much brute force when fitting,and reassembled out of line, the other reason is you are buying **** part, not genuine.