2013 Super Duty long bed 4x4 have continued vibration seems like wheels and tires have had dealer replace tires and change wheels and replaced shocks. Now they are saying some do it worse than mine and basically refuse to do anything further. Have friends with 2011 and 2014. The 2011 is King Ranch and has no vibration 20" rims and tires factory. The 2014 has similar vibration bounce but stops faster than mine as mine continues for quite a bit longer. See numerous threads regarding frame harmonics but no solution to fix. Like truck other than this annoying bounce. Worse in rear seat than front. Any new info on Ford actually helping to solve this problem?