There should be a check bolt about 2/3 rd's up one of the sides of the t-case. Remove the bolt, and stick your pinky in the hole, you should be able to touch fluid. Same with the transmission. Definately check all the U-joints on the driveshafts as well. Crab the driveshaft, and wiggle it back and forth, to see if there is any slop in it. Look at the u-joints while moving the driveshaft, to see if you can detect any wobbling.