Sorry for digging up an old thread but I'm having a similar issue. Was having the clunking/grinding sound as seen in first video, when the tranny tech at a local auto shop was checking it out, he went forward in first, then reverse and back and forth a few times and the noise went away. (Just replaced trans fluid) and he told me that it might have been the new trans fluid getting into the center diff and it being dry for a bit or something of the sort. Now my car makes that scraping howling noise as in second video, but mainly when in gear and off the gas coasting. Its extremly loud.. think its my center diff?