I have had my 2015 hd for 6 months and have had it tested several times and they did a pico test and tried something changing something on the exuast and didn't work, next changed the fan clutch that didn't work, mine has a vibration usually around between 2000rpm and 2200rpm, most noticeable when pulling a hill. very frustrating that they can't fix it, they even tried telling me that all trucks have vibrations at certain rpms, well I have had several Chev and Gm trucks before this one and have never had this problem before. they know it does it and they know others are doing it so why are they figuring it out is my question?
