39 rear

[flathead48]

Trying to help a friend has a real nice 39Ford 2 door, stock 3.78 rear with a Mitchel o d . When he makes a sharp left turn there is a high pitch almost like a scraping noise. We pulled the hubs, rollers were find hubs in great shape repacked them with proper grease but did not help. Presently leaning towards spider gears ! But that is a lot of work to do on a hunch of an amateur. Any suggestions, thoughts ,ideas would be greatly appreciated.
Thanks Rick