Help Truck Makes Scraping Noise and Grinding Noise

I have a 2010 volvo 670 and it keeps making scraping noise just like when the breaks are bad. It only happens when I hit a bump or go down a hill. Also, it only makes the noise when I'm going over 60MPH and it sounds like a break is bad a makes the scraping noise. It doesn't make it always, but it comes and goes. When I put the truck in neutral it never makes the noise going down a hill or over a bump. Took it to the shop and they said transmission is good. They fixed a few things, but the sound comes and goes. "Drain, inspect rear differentials, remove and inspect driveshafts, and reinstall drive line, tighten end yoke and repair loose universal joint cap". The noise is driving me crazy and no one seems to know what it could be. Does anyone know what it could be??

 

it sounds like a bad break scraping. It doesn't rattle just scrapes. It has about 650k miles and it an eaton transmission.

 

Airbags looked pumped up, but I hear the noise from the front somewhere. It just scrapes like a bad break. Could the valve cause this? Comes and goes, but when its in neutral you can't hear it.