The truck is worse than before now after the dealer said it was fixed.
They told me there was a tire with a bubble in it, at high speed the bubble stretches and moves to a lower location near the tread. Therefore causing the vibration. The Dealer replaced the left rear tire. They dealer also Radial Force balanced all tires, they did have to rotate the tires on the rim to properly balance. The mechanic stated the truck drove ok or as normal, however did feel "Only road and some frame beaming which is normal". I disagree.
They performed visual multipoint inspection including tire & brake, etc. Drivetrain inspection, tires, suspension, exhaust, etc.
Mechanic said the vehicle is pulling at high speeds, the truck didn't pull when I drove it.
They also performed Wheel alignment.
I arrived at the dealer today to pick up my truck, at which I test drove it before giving the loaner back. The truck is the same or worse than when I brought it in. I left the truck with the Service Writer, he said he would talk to the managers at what can be done.
He called me back to say, they have done everything possible and nothing else can be done. I even mentioned trying Michellin tires, they said I can go buy them myself.
This is a Denali, should ride like a basic truck or way better. I have owned and driven many trucks old and heavier than mine, none of the vibrated at highway speeds.
To summarize, I am very disappointed.