Grinding sound while rolling

Hello Ihrse, BJ 1997 TD 90 PS 152tkm wheel bearing according to 2 workshops and Tüv complete i.o. for some time a grinding noise bothers me while driving. It is best to hear it when rolling at idle speed. I would type it from the front but in the car it is very difficult to locate it. Was already in 2 workshops but they dismissed it as a rolling noise of the tires. To my opinion this can not be for the following reasons: 1. Also on the dirt road, where through the Unter 2. as soon as I step on the brake the noise is gone! 3. The tires are almost as good as new and with other tires (winter tires) I have the same noise. When I pick up the car I have a grinding noise at the back of every wheel crashing{ the workshop said that would be normal and not to be heard during the ride. (nothing can be heard on the front wheels when I turn the brakes) Brakes in front are also complete 2 months ago The sound disappears at about 50 km/h, but between 150 and 160 is again intensified … over 160 to limit lt. Tacho just over 190 is nothing more to hear. what do you think about it? It is a rhythmic grinding/singing noise faster or slower depending on the speed. I strongly tap on the brakes but the workshop, which has only recently completely renewed the brakes, denies the vehemently. How can I narrow this down or locate it better. the suspicion they want to press for improvement or replacement. thank you already for your tips Greetings Tom