Delayed cold 2-3 shift

Hello, if you're looking for shop manual information or photos, you'll have to acquire one. We don't have the ability (or legal right) to publish that information here in this forum. I would just suggest, however, that at 284,000 miles -- there could be a myriad of things happening with your transmission, and that this will likely require tear down and inspection to determine the extent of internal issues. Have you performed any diagnostic testing using a proper diagnostic tool - are there any trouble codes in memory? If you have "crud build up" after all, I assure you it is not isolated to a single location.