I have a 2007 Chevy Silverado w/manual 4WD. Engages fine...works fine. When I go back to 2HI it takes 15-30 seconds to disengage. With a loud bang/clunk. Hasn't done this for the last 5 years now it started. Dealer changed lube in differentials and xfer case. Dealer rebuilt front differential and acuator. Dealer rebuilt xfer case and found a badly worn gear. Same problem exists. They have definitely tried to fix it but now they tell me this is "normal" and offered to show me it happens in a new 2012truck. I wouldn't waste my time because I KNOW how my trucks have operated.
Anyone else have this problem??

 

Problem Solved! Believe or not, it was the tires causing the problem. I went to another dealership and they took all 4 tires off a brand new truck, put them on my truck and problem was completely GONE! The tires were only 1 year old and had about 20K miles on them. Firestone Destination A/T. Dealer then put on my old tires, rotated them and filled them to max pressure of 44psi. (rating stamped on tire) Problem is definitely smoother and quieter now but tires will have to be inspected for problems.