2011 Volvo VN670 vibration Issue

My 2011 Volvo D13 Engine with Ishift Tranny started vibrating. Its not so much vibrating as it seems more like back end is bouncing all over the place. It happends only with the speed between 55-60 miles with 58 miles being worst. Any other speed truck runs perfectly. Injectors were replaced so its not it ... plus rpm when it happends its steady, it doesnt jump. Air suspension, airbags, shocks, springs, and the whole driveline plus everything that has to do with suspension were checked and everything is ok there. Tires are all new all around. Any ideas what might be causing this

 

Also when its loaded you cant almost fill it. Only when empty or bobtail

 

Tire instalation was done by Pomps Tire. They checked it twice. Front wheels were balanced plus they did 3 axl alighment. You dont balance rear wheels but when they put them on the balancer they are all within the spec.

 

I said that they already checked it if it was centered and Balanced and everything seems ok thats why everyone is wondering where is it coming from

 

They are all Virgin Goodyear

 

I was at Pomps Tire again and they said they never heard of the stand to inflate tires laying down. They do all tires needs for local chicago Panske Ryder and Volvo dealers and they never had someone ask this. The guy looked at me like i just landed from the moon. He even showed me special stands that they use to inflate tires