lound clunk

the clunk happened when I was acceleration from a stop as soon as I hit the gas. I did hit the gas a bit hard if it matters. The clunk also happened after that when I hit the brakes hard. The clunk seemed to come from the middle of the vehicle-transfer case maybe? both times after the clunk the vehicle was still driveable.ie no more noise.
*** I was driving in part time 4x4 because last weekend I snaped the rear u joint clamps that hold it into the rear yolk and thus the rear driveshaft had to be removed.
what is this clunk. is it the result of driving with no rear DS. or is it T case related

I know this might sound crazy but I had a simalar clunk and only heard it in 4wheel high and low. Come to find out it was the left engine mount . It was totaly shot and the bolt was hitting the the top of the mount. Changed both engine mounts and no more clunk.