drivetrain noise

[09 lex 250]

im getting alot of noise in the rear drive train in the bmax.i tried replacing the rear cvd's in the car but still getting the same result.also tried relubing and cleaning the rear diff as well but still have the same issue.i was looking at a friends bmax (same car).when i spun the wheels to feel how the diff was,it was ultra smooth,nothing like mine.could this be the diff balls? when i spin mine i hear the high pitch noise as i rotate the diff back and forth.and mine feels a little crunchy.should i set the diff a little looser than the front? when i had my 44 i ran the diff alot looser? any advise would be greatly appreciated!

car drives super smooth other than that