Had this problem before about a year and half a go. When accelerating, it hesitates. On and off while driving. Brought it to the dealer and couldn't pin point (Had to be an on going problem). Finally, 6/5/16 driving 70mph on a 1hr drive car stutters badly upon acceleration again, but this time permanently (still drive-able). Brought it back in now, Transfer Case problem. $4k+ to fix. We have an Xdrive.