Ok, all you whiners. You know who you are.
I've just seen a reference to a new TSB 05-12-6 which addresses diferential whines.
If yoiur diff whines, Ford has a parts kit that includes pinion and ring gears, pinion bearings, and carrier bearings, and some seals.
It is not a recall, so I think (but am not positive) that standard warranty rules apply. If you are in warranty, its Fords dime - if you are out of warranty its your dime.
So visit a dealer near you and get your own personal copy. May be of some help in getting a full rebuild!