I have a 2005 Colorado 5spd 4wd that was recently wrecked in the front. I have been having issues with the 4wd. Replaced the transfer case. It's reading Service 4wd on the dash I'm possibly leaking transmission fluid as well. When I am in drive it makes a loud popping and snapping sound. It was doing it in reverse at first. Now it won't move in reverse. Any thoughts ?