I have a whiring noise (sounds like a jet engine but not loud) while driving. It does not change when I put the truck in neutral or rev the engine. I press the brakes under speed and it does not change. It does not change while turning. Starts at about 5 mph and gets louder with speed. I checked the drive shaft where it enters front differential and rear differential and there is no play in it. I replaced both front wheel bearing/ hub assemblies and the noise is still there (thought it was coming from them at first). Today I put the rear up on jacks and put it in drive and there is a loud grinding sound coming from the rear differential. I looked at some videos on rebuilding the rear diff and it looks beyond my abilities (primarily because of the specialized tools they used). Any recommendations on what I could check next to confirm? Also, what's the going rate for a rear end rebuild? Thanks.

 

You need to post in the 3rd gen Ram section.