The bolt that holds the cross pin it is notorious for breaking in GM vehicles. Be very carefull taking it loose. It won't break at the threads, it'll break after the threads, leaving the unthreaded part of the pin in the cross shaft. very hard to get out if it does that. Shouldn't be as much of an issue with the old diffs, but I've seen lots of newer ones do that. Sometimes they'll break when they were put in at the factory.
