Cummins isx 400 st wobbles!

Hi, I have a 2008 volvo with a isx 400st engine. Lately I am feeling some wobble coming into the cab, and can be felt through the stick shift too. At low speeds pulling a hill, it gets pretty bad, shaking the truck cab back and forth like crazy. There is no noise, I get great fuel economy and no loss of power. I thought it was the drive line, but one morning I started truck and it started to wobble from side to side like an earthquake!
I depressed the clutch, there was no change. Giving it some rpms only made it shake worse. I got out, did a visual inspection and found nothing wrong. Shut the truck of and restarted it, and the wobble disappeared! Now I get intermittent wobble on the road while driving, worse when pulling hills with a heavy load. The wobble seems to be effected by the road bumps, as the bumps seem to either make it worse or less. I stopped at a shop, they checked everything out, tires rims, bearings the driveline, basically everything I could think of, and found nothing wrong. The engine has a new turbo, new Dpf, new egr cooler bunch of new sensors, and other things. It always had a shudder or a misfire when idelling. Please help, I think it is my engine. I thought it might be a bad injector, so I have been using injector cleaner for the last 3000 miles with no change. Thank you.

 

No, still originals, as far as I know.

 

Okay I will take it to a volvo shop and ask them for the test. Thanks for your help, I will update once I know more.

 

That is what I thought too, but then after that cold idel shaking that later went away, I am not sure anymore.