Silverado 4500/5500 coming next year.

The Maxforce diesel engines that Navistar developed for use in their smaller trucks is an unreliable, poorly designed engine. They are very difficult to keep running reliably, and the Maxforce warranty claims have taken a huge toll on Navistar. Navistar needs the reliable Isuzu/Dyramax technology for it's trucks, and GM needs someone to build midsize trucks for them. Thus, a joint venture. "How Convenient".