a loose bearing will allow the drum to twist out of alignment with the shoes, especially on a turn. The misaligned shoe engages on one edge or another and causes the growling noise. Woven linings on cast drums squeal more than molded linings. Try tightening the bearing nut one cotter slot. Ford bearings should not be tight, but if they make more of a clunk than a light click when pulling the drum in and out, they are too loose.