when driving about 30 t0 45 mph turn left and right ,back and forth listen if sound changes when weight is change from left to right you might find something on u tube to show this ,mine went out about 160k on my old jeep. just do them both .
Tried turning wheel at 30to40 mph side to side & droan, roar does not change and is in the rear. I only have 75K, read that the drive shaft may be the problem?
they normaly chirp ,check rear diff fluid ,also check rear e brake i had mine wear out on my 1998 grand and it made a heck of a rackete,jack up jeep so rear wheels are off the ground put on neutral and turn your rear tires you will hear it .