This is nothing new, folks.
Navistar, the parent company of International Truck and Engine Corporation, is having a bit of a finanical 'issue' of late. Their accounting is in shambles, they haven't reported earnings in over a year, they're in severe danger of dropping off the NYSE--if they haven't already--and their CEO has admitted, jokingly, that he wants to find a buyer for the company.
Ford and Navistar have a contractual agreement to share warranty repair costs on the 6. 0 liter Powerstroke diesel engine, and a contractual price point structure for the 6. 4 liter engines. Thus far Navistar has not held up their end of the bargain on either contract.
Due to Navistar's accounting problems, the money is not available 'on paper' and Ford is exercising their only option at the moment to appease their shareholders, which is retrieve the money via a lawsuit.
Welcome to big business, where fathers sues daughters, sons fire mothers, and everyone eats dinner together at 5pm.