[Fulltilt3]

This is my first duramax and so far at 950 miles I am very very pleased. 17.03 mpg on my second tank. I have a couple of issues that have materialized just after 500 miles. I can feel a resonating vibration in the go pedal and the floor board. My wife can even feel it in the passenger side.

It is not a shudder type vibration as it feels more like a humming. I really am having trouble describing it.

I am hoping someone will be able to tell me that it is common and it will go away, or here is how to fix it.

It comes in between 60 and 70 either on the way up or down.

Any thoughts or places to start???

Thanks!!