Diagnosis
This is usually a foreign object caught between the washplate at the bottom of the tub and the inner tub. Coins, bra wires, and screws are common culprits.
How to Fix It
Unplug the washer. Remove any visible debris from around the washplate. Tilt the washer back and check the drain pump filter housing at the front-bottom for objects. Manually rotate the inner tub by hand to feel for and locate the obstruction.
If That Didn't Work
The noise could be from worn drive pulley bearings or a damaged spider arm. This requires a technician to disassemble the tub assembly for inspection.
Heads Up
Continuing to run the washer with a grinding noise can score the stainless steel tub or break the washplate. Stop using it until the object is removed.