Noise in rear of Nissan Altima

[dominicus]

For some time now I have a bad noise in the back of the 2002 Nissan. It is fine driving level and everything. When I make a turn onto my driveway or a parking lot from the road it makes a grinding type noise. When I back up, of an unlevelled area,the same things happen. In other words when I make the turn one wheel at the time comes over the ridge of the entry. Every thing under the car seams fine to look at. I went over things under the car with a rubber mallet. That did not find nothing. We are guessing the shocks. I do have someone that helps me with most of my car needs ,but this is a Nissan question. I have 103000 km on this car,and the rear brakes have been cleaned and or replaced,three (3) times. They are fine by looking at them this time. Any Idea's that may help me?
Thank you