If I grab the shaft and try to move it back and forth quickly, I can hear a sound in the 3rd - almost like gear teeth having a slight amount of space between them before they actually touch. I am hoping this is normal.
Put it in neutral and grab the driveshaft with one hand and grab the piece where it bolts next to the transfer case and rotate. see if there is play right at the ujoint. do the same for the ujoint next to the 3rd member.