Vibration from rear of 03 D2!

[spm1976]

I have a 2003 Land Rover Discovery 2 and am recently having a vibration coming from the rear of the vehicle. It is vibrating in the rear of the vehicle at any speed when driving straight; however, when turning it becomes more like a shudder in the rear. I have pulled the U-joint & it is a little worn and the Flex Coupler is somewhat dry-rotted with few cracks. I am about to pull the Diff. & go thru it but I would rather know that it is definitely the problem before I have to do that! If anyone else has had or is having this same issue and could possibly contribute diagnostic information, it would be greatly appreciated.