Steering System Noise Definitions: Grinding
WARNING: This page is about a different car, the 2007 Ford Pickup, 2007 Ford F550 Super Duty, 2007 Ford F450 Super Duty, and 2007 Ford Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.
Grinding is a low frequency noise in the column when the steering wheel is turned. This is generally caused by interference between moving components, such as steering wheel to shroud.