Spare Tire Mount

The harness that holds my underbody spare tire in place is no longer working. It is a steel thread that turns on a crank, well the thread has begun to splice and is becoming tangled somewhere in side the mount preventing it from being operable. As of right now, it will come down about 1 foot from the harness, and will go up about 6 inches. Other than that small range of motion the crank won't turn.
I'm assuming I will have to replace the entire piece in the end, but has any body come across this before?
Any idea how much this will cost to replace?
Would my warranty cover something like this? It is a standard bumper-to-bumper as far as I know.

Thanks for all the help.