Ring and Pinion have a design defect.
I am not impressed by Fords lack of service. Four repairs to common ring and pinion design problem and they still have not made any offers to replace or refund my money.
I spent over $48k on this lemon and Ford wants me to just accept that the ring and pinion make a loud whining noise.
Rack and pinion.
Have Ford do a power steering flush, it will make it a lot quieter.