Another case of vibration on 01 pete

Hello everyone. I started having a problem last week on my 09 peterbilt 386,. which is a really bad vibration under acceleration which is get worse under load. I took the truck to a Pete dealer the same the problem started they spent two hours on truck and they said it's the motor mount . I change all the motor mounts problem still there I should know better to stay away from the dealership. My dashboard already came loose due to that problem. Truck already been to three places everything had been check nothing is loose everything are tight as they supposed to. Any help or thought would be really appreciate. Thank you.

 

Hello everyone. I've been having a bad vibration issue on my 09 Pete 386. The problem start at 40 up to 60 mph when the Truck is under load. The truck already been to three different places the first one was the dealership they said it was the motor mount all six of them. Changed all the motor mount no different problem still the same all the drive line been check with no issue steer tire been balance. When the truck started vibrate it did put a slight delay on the RPM gauge which kind of make it bounce up and down while the vibration is in place. The problem only occur under acceleration and get worse when the Truck is under load. My dashboard already came loose within that week of having that problem. Any help or thought would be really appreciate.thank you all.