If it is considered "frame damage" and is not disclosed it is against the law and you will win in court...of course it will be a lengthy process in court if you cannot settle the issue with the dealership outside of court, if they are a reputable dealer they should settle the issue by taking the truck back or settling with you, if the car was disclosed to you as "being in an accident" or is salvage, you are s.o.l.......hope this helps, feel free to pm me if you have any other questions