Snapper
I've just had a lot of experience with this lately. I've replaced ALL the joints in my rear driveshaft. I need to post an update to my situation in my "growling rear end" post and will try to do that tonight.

The joints in the yokes are easy to check by removing them from the flange of the tranfer case or diff. I applied as much force as I could to the joints with everything hooked up and I couldn't tell I had a problem. As soon as I disconnected the yoke and rotated the joints in my hand, I could feel binding in the rear one. I would recommend doing this check first.

Changing joints is not difficult but a press makes installation a whole lot easier. I was a little intimidated by the process so I got a friend who's done numerous u-joint jobs and has a press to help me out. I would attempt it alone now but I would have an extra joint on hand just in case. Adam's writeup gives good directions. The two yoke joints were actually pretty easy. The u-joints in the double cardan joint are a bit tougher <img src="/forums/images/graemlins/shiner.gif" alt="" /> but we got those done too, after a fashion.

If you do this job, don't forget to lube the new joints up once you reinstall the driveshaft but don't overdo the grease on the driveshaft itself. A half dozen pumps into this zerk is probably too many.