I have a 2003 Toyota Tundra that is making noise towards the back of the cab. It sounds like metal on metal banging/grinding. It only makes a noise when it is going above 20 and it does not speed up if the car speeds up, but it does get louder. The auto repair people i took it took replaced the stabilizer on the driveshaft but think the axle is bent. I'm not too happy with the work these guys have done in the past so I want to get a second opinion. Any ideas?