I have a 2014 V6 2wd with the towing package and locking diff . My truck has a slight vib only between 20 and 30 mph . You can also hear it but if you roll both windows down you can't notice it . As I replied earlier in this thread I took it to my local dealer for a oil change and explained the vib issue . They checked it out and said it was normal so to say the least I was disappointed . They don't have that vib tool yet to help locate the area of the issue so they did say to bring it back after they get one and theyll check it out again . So my next oil change I'll probably have them take a look . What's strange about my vib is when under acceleration it doesn't do it or at least you can't feel or hear it at all . But slowing down , coasting or just maintaining speed between 20 and 30mph is when it does it .