I have been hearing a rotational metallic knocking when getting on and off gas pedal. Also when clutch is pressed. Fairly certain it is coming from transfer case area. I removed case housing today and chain has a good 1 1/2” to 2” of slack. I can almost push it and touch housing. I can push it and touch shift mode fork. I tried to post pics and video but apparently the files are too big. How much slack should I have?