Shakes or Wobbles problem
2005 Chevy Avalanche V8 Two Wheel Drive Automatic 50000 miles
The Chevrolet dealer checked the vehicle over and then changed the motor mounts out and the transmission mount. The vehicle has a vibration in it. In neutral it is not noticeable, when it is put ion gear you can feel it at idle and up to 60 miles per hour. What could cause this problem. Harmonic balancer,
Flex plate, torque converter, drive train or rear end?
If it vibrates at idle in gear I would rule out driveshaft and axle as that needs to turn to vibrate. But your harmonic balancer could have broken the rubber and moved. An easy way to check is to put a chalk mark on it on both pieces then give it a quick rev and see if it moves. Also the flex plate could be cracked, the torque converter bolts loose or a weight could have fallen off the converter. Unless the trans has been worked on recently and the converter has been changed as it may bbe the wrong one.