I've been looking through the forums for months and I've been unable to find someone who has the exact same issue as I have. The issue started initially when the vehicle was in 4-wheel drive and occurred much more with the wheels turning. However over time the clunk began as soon as the vehicle was put into four-wheel drive. I've attached a video, and I cannot tell if the issue is at the u-joint or the t case, obviously hoping that the former is the issue. Any input would be greatly appreciated!