on most driveshafts there is only 1 or 2 places they fail. on the rear drivshaft it is almost always the part that goes on the axle's yoke. you want to pull off the cap (being very carefull not to loose/nock free any needle bearings) and make sure the needle bearings are all there. the u-joint on the slip yoke side has to be dissmantled for a visual of the needles, but it should flop around freely and there should be no play. the front constant velocity jint should be free and have no play, they never really go bad much. the fron yoke side u-joint gets inspected just like the rear.

Check for ANY movement in them... You get under there with The emergency brake on tight and the gear shift in neutral and you push, pull.lift and shake the driveshaft with all you've got. If you get ANY play out of one of them replace them both.
Big Jim

Thanks fellas!

I will try to troubleshoot the rear driveshaft tonight and I will be sure to post my findings!