I have been looking at a 2013 Dodge Ram 2500 4X4 Big Horn edition with a Cummins turbo diesel. The switch for the 4 wheel drive it on the dash as a knob, instead of being a shift in the floor. Several friends have told me that they have heard of people having issues with the 4X4 locking up and going out. They have only heard of it going on with the the one's that do not have the 4X4 shifter in the floor. Has anyone had any issues or problems with them?