All, I have a 2014 Sierra 4x4. I purchased it new about 4 months ago and drove it from Illinois to Louisiana and it drove absolutely great, better than my wife's Cadillac. About a month ago while shifting into drive I heard a bang in the transmission area. I immediately could feel a vibration in the gas petal and steering wheel after that.
I brought it in to a local dealer and the advised that they balanced the tires and one or more ( I'm not sure ) was out of balance by up to 5oz's. Just before I brought it to the dealer I had a local tire shop check them and he said they were perfect. Okay so I get the truck back from the dealer and the vibration is worse. My 2003 silverado with 300k miles doesn't vibrate like this. I mean my right foot nearly tingles after a while like I'm on a lawn mower.
So just the other day, while driving at 76mph I decided to reach over and shift it into auto and when it engaged I could feel the vibration get stronger. It never did that before either. I believe the problem is in the transmissions and that is why the dealers never find the issue because GM will not allow them to change it out or they don't believe that's the issue. I have another appointment in a few days with the dealer. I'll keep you all posted. Sorry I was so long.
