i just fixed mine with the same problem,took me 10 mins and no parts!! It is quiet again,this is what i did:-Pull out freezer draws, Remove plastic cover(2 screws at bottom,clips in at top), You will now see a fan blade,which was causeing the noise,it has slipped too far on the shaft,pull fan forward so the blades are no longer hitting brackets,spin blade to make sure of free running,refit cover,Hey presto noise gone!!
Tim, March 2009