The bell is where the U-joint is. There is a bushing in the tube behind the U-joint. The bushing is difficult to remove. Usually an after market bushing is driven in which drives the old bushing farther in, but that doesn't hurt anything. If the bushing is real bad, the joint will scrape against the bell. I would recommend getting a service manual if you intend on replacing the bushing. Its not that complicated, but a service manual will be very helpful.