You need to find a repair shop who can measure your frame with digital frame machine.
There are certain points they can measure, that are the same points that were measured when the frame was built at the factory. This data base is for all cars/trucks and is software in their machine.
I went threw this 5 years ago with insurance company when I got rear ended while driving my Nissan Titan that I had.
Insurance company insisted the truck was ok to be repaired new rear bumper and passenger side bed skin.
I found body shop in my area who had frame machine and measured the factory points and proved my frame was bent.
Insurance approved frame straightening .
I hope this is not the case with your truck but needs to be checked.
If frame is bent it will cause the truck to not track correctly even if a 4 wheel alignment is done it cannot make up for bent frame.
I got the truck repaired and traded it in, of course with car fax I lost "resale value" even though the accident was not my fault.
This is called "diminished value" I got my insurance COMPANY to refund this amount because it was "not at my fault accident"
I will see if I can find pictures of my truck it did not appear to be bad.
My accident happened in Connecticut and I drove my truck home to South Carolina.
Regards
Don
