I have the same problem. When I am backing and turning the wheel to the right, I get a grinding sound from the right front end. The wheel is not even to the stop when this happens. I don't hear anything when backing and turning the wheel to the left. And this started when I had the RF wheel bearing replaced a couple of months ago.

1998 Contour SE, V-6, ATX, everything stock (70,000 miles on original ATX and water pump and counting)