All you will hear back from a sweet, female voice at Ford "customer service" is that your vehicle is out of warranty - tough luck. Also that they have "not heard of this problem before".  That's what they told me.

It will cost you over $1,000 to replace the rear axle. 

Again this is a major safety issue as these vehicles age. It will evidently take several people dying before Ford will even send a bulletin to dealers asking them to check this at oil changes....

I'm glad no one was hurt in your case.

Jim at Dawn