Just got my 2001 S Crew 4x2 back from the shop. I have had a roaring noise coming from underneath. Thought it was a pinion or axle bearing. They said they could not find anything wrong with the rear end after $90 for the lube and a half hour of labor. They said it could be the drive shaft and it should be balanced or replaced. I didn't believe it. They put it up on the lift and put it in gear and showed me where the noise was coming from. Sure enough it "seemed" like it was coming from the middle of the drive shaft. Getting closer to the rear end... No noise.... It sounded just like it was coming from the driveshaft. No vibration so I didn't believe the balancing thing would work.

Anyone who has an opinion or can shed any light would be greatly appreciated. The dealer is my last option. I hate writing a check just for walking in the door. Could not find anything on these forums addressing this. He also told me that there is paper inside the drive shaft that could have come loose. I am getting lost at this point.
Thanks.

 

I'd put it on the rack or some jackstands and try running it up to speed and listening at different points along the axle with a stethoscope. While driving, get it up to speed where you hear the noise and try pitching the truck left to right a little. If the noise shifts from side to side, you may have a carrier bearing concern. Pinion bearing noise usually stays constant regardless of direction, but may vary pitch slightly on throttle tip in. Ultimately, the only way to find out what all blowed up is to tear down and inspect all the bearings in the rear axle.