GM response, not a safety problem, no recall - yeah but your product has a serious defect. it vibrates and shakes. For them to say that it is not safety related by default tells me they know the root cause. If the vibration was due to ball joints / tie rods / hubs and studs, those are safety related. They know, they won't tell, they won't fix ... someone has done the risk / profit / fix calucation and the customer has come up a loser. All we need is Goodyear, Firestone, Michelin, and Firestone to give GM the middle finger and say "Our tires are fine, fix your truck". Think how much money those poor suckers are losing with multiple tire swaps back and forth. There has to be some negative publicity that GM dealers are pushing to the tire dealers... "oh no, the tire has a road force number of 30, it sucks, these (name manufacturer) tires suck"... Road Force of 30 works on every other vehicle just not a 2014 Silverado