2006 silverado transmission/transfer case issue

[Ronnie2006]

My 2006 chevy silverado has an issue while driving it will act like I shifted in neutral I get pulled off road put truck in 4hi it will make a clunk then I shift back into 2 wheel drive and everything works fine seems to only do this when I get off the gas happens at any speed and any temp there are no codes showing up either any ideas