Hi to all again,

I got this van after it had an accident in the back.  The engine was saved by the towing unit, but the rear hatch was hit and the area where it locks was pushed in bad.
Now, as I try to reverse it, shudders like nothing I’ve ever seen.  Yet, going forward, has no such syndrome at all.  
So, I was hoping, some of you might know exactly what it is.
Anyone?

Best wishes to all,
Zoltan