Vibration at 140 km/h

Hello!

I'm looking for your help with the following problem:

I've got my FL S8 BJ. 1999 with 165,000 km the complete suspension can be made:
- Bilstein B6 with original springs
- MEYLE HD front complete, rear partly
- Goodyear F1 on 18 inch OZ rims.

Danch ran the car great, but only for 8 hours...
I was skilled enough at about. Take the curb 50 km/h back right. Danch had vibrations from approx. 100 km/h, at 120 km/h the most pronounced and decreasing to maximum speed. To do this is a whirring noise when taking gas away, i.e. load-dependent.
The tires were weighed x-fold, even under load (600 kg). A test-proof change to winter tyre set also showed no change.

The following changes were made:
- 3 x Goodyear F1 (2 due to high altitude, one due to possible damage by curb)
- complete set of rims (due to possible damage)
- Cardan shaft (because of altitude play)
- Front brake (due to brake scrubbing)

Now the erring noise is gone (height stroke cardan wave), the brake front is also quiet.

However, the vibrations have only shifted to a range of 140 km/h.

According to the workshop, dampers/springs, wheel bearings and drive shafts look good. Gear seems to be fine, how the differential can be tested I don't know.

==References== I've read vibrations, but it's probably not about tyres/wheels. Nevertheless, a sentence of Dunlop is to be raised tomorrow.

Does anyone have any idea before I run out of money for good?

Thank you very much in advance!

Frank