I was doing some plumbing on my 2011 3950. I opened up the underbelly and discovered to my dismay that the cross-member right at the front spring hanger has broken. From the looks of the rust and wear on the broken pieces, it has been this way for a while. If you can, I recommend checking yours.
Note that the other end of this cross-brace is attached but that some of the web rods are broken too.
I'm currently discussing repairs with Lippert and Dutchmen.