Hello together. So I hope someone can help me here. My problem: I have an Iveco Daily 35c13 Jg.2000 Long wheelbase high roof. I let the differential check and fill in the thickness oil 80w140 and replace the middle bearings of the cardan shaft. Beiu the first ride I felt a vibration that starts at 80-83 kmh and no longer stops the faster I ride. The vibration transfers to the seats above all and there is a roaring in the bus. Whether on load or After that, the Mechanicker and I tested everything on the lift and also ran without wheels at the rear with over 80kmh, exactly the same effect. After that, complete cardan shaft testing and balancing. Vibration still there…….. We don’t know what to do any more soon. Greetings Stefan