It's very annoying! I have my mechanic trying to figure out what the problem. I changed the sway links because they were loose, but didn't stop the popping that the problem is causing. My mechanic has told me he has heard from a lot of other mechanic that is hearing the same problem. He has said he has been told that a few mechanic are saying it could be in the transfer case, but no one knows for sure. If anyone else is having this problem or knows what is causing this problem please let me know. Thanks