Whining noise ir rear end
 

My 2002 ram 2wd 4 door is having a loud whining noise coming from the rear end. I put the truck on jack stands, removed the rear tires & brakes, started it & put it in drive & it made a loud whining noise from the area of drive shaft rear end. could it be a bearing in the rear end or the U joints? Has anybody had this problem? PLEASE HELP. Thanks Dave!!!