So she started making a slight bumping noise from the rear left. It became more persistent and began sounding more like a groaning or creaking. Seems to be more when I am turning at slow speeds or hit a bump at slow speeds. It never whines, and just yesterday when I stopped and then released the brakes it seemed to hold the rear end high and then settle back down a bit. From the bumping and groaning I thought it would be the differential. But from the holding high and release I'm thinking brakes. Help?