Now, Back in the early 80s, a financially troubled IH stopped production of the small trucks, restructured the large truc operations under the name Navistar, http://www.navistar.com/index.aspx
and spun off the farm equipment to become Case http://www.caseih.com/
The corporate history pages from there say that Case was a separate company from 1842, until 1999, when they merged with New Holland. It doesn’t seem to say that they were ever spun off by International Harvester:
Oh, I see. There’s a long pdf document available under the Case IH history. It appears rather convoluted. and gives the impression that IH farm tractors were eventually a division of Case. Looks messy:
I’m guessing the assets they bought had nothing to do with the truck line, which eventually became Navistar. International Harvester farm equipment became Case IH.