1998 GC Rearend Noise?

Just out of the blue I started getting this whining vibrating noise from the right rear of our jeep. I pulled the rear cover and every thing looked fine and replaced outside axle bearings on both sides and still have this noise . It almost sounds like a bushing is bad and transferring normal rearend noise directly to the inside of the vehicle , but they look alright from a visual stand point . Has any one ran into a similar problem , or is there a common problem with these jeeps? Looking for any help .. Thanks Runk ....