Possible frame problem. Warranty?

Bought a 37BH silverback in June '13. Notices that lifting the fiver on and off the truck that there is a lot of flex in the front port side of the coach. Didn't think much of it until I noticed on our last trip it developed a vertical crack on the exterior wall above the corner of the master slide on the coach wall.

I can't find anything about warranty and am worried that 3 years in I'm on my own.

Any advice on where to start?