I get a roaring noise starting about 60 mpg to 70 mpg and then it seems to disappear. This is when the vibration start to kick in and I can see it shaking the mirrors slightly. I am thinking bent drive shaft ?? but I am not sure. I bought this Montero about a year ago so I am not sure about prior history. I can't see any markings on the drive shaft that would indicate damage.... any suggestions thanks Mike Cunningham