I am very glad that my manufacturer spec'd a heavy duty Lippert frame.
If anyone here can do the fix, you are the one.
I agree that trying to jack it back into place will likely damage other areas....
The only way I can think of fixing this would be to raise the box off of the frame.... That is a HUGE undertaking, and will need some thinking outside the box to accomplish.
I am interested in how Lippert would fix it, and what your plan of attack is.
The suspense is killing me...
Seriously, I am sorry that you are facing this issue. No one should have to face this sort problem.
