I have a 2006 silverado 1500 with 53,000 miles on it. I have the 4WD shift on the floor. I can not shift on the fly ( not sure why when my 2005 trailblazer could with pushbutton). My problem is its difficult to shift in to 4WD and when I get it there the vehicle feels very squirrley in the front end. Also when I shift back it doesnt always come completely out of 4WD even though 4WD light goes out and there is a loud sound coming from front axel area like its still in 4WD when I drive.

 

When you take the vehicle out of 4 wheel drive it is a great idea to back up. This usually frees up the transfer case and takes it out of 4 wheel drive. You don't have to back up a whole lot 6' is good. That's the good part about the push button is the shift on the fly but with the manual shift on the floor you have to stop before you engage 4WD or out of 4WD. I prefer the shift on the floor bc there is less electronics involved and problems