Where is FMC getting their steel from?
Are their frame rails open C-channel stampings? Or hydro-formed tubing?
What sort of anti-corrosion treatments does Toyota specify for their chassis and suspension parts?
I bring these questions up because truck frames are usually made from heavy gauge steel. Even with less than ideal rust prevention measures, and being used on salty midwest roads, you would think that the frames would hold up for at least 10 years before rotting away.
Fords used to have this same problem, due to insufficient removal of impurities in their recycled steel. Up until the mid 90’s their cars would literally rust on the showroom floor wherever moisture would get trapped.
Toyota frames have always been light gauge boxed frames and have always had rust issues. I don’t know how the class action progressed but this has been going on for years. What astounds me is how GM and Ram get away with the same issues on their boxed truck frames. These type of fabricated box frames are prone to these type of rust failures. Google Chevy truck taco. It’s called “tacoing” because the trucks fold in half in the middle.