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.