I believe the fan was OK. The belt wore through the ac line but the belt did not break and the accessories all turn as they should. The motor temperature did not go up.

What I found:

The flow test went well. The transmission pumped well over 1 quart of fluid within 10 seconds. There was nothing nasty in the transmission pan. I checked the "check ball" up near the front transmission cooler anyway and it moved freely with no debris so I left it in place. Installed a new filter and a deep pan just because it can't hurt. Flushed out the old fluid and put in new ATF +4. Much cheaper to buy at Amazon ($30 for 5 liter jug) than dealership ($45 for 5 liter jug) The good news was the transmission temperatures were good. Maybe 160 on the highway empty, which is at least 15 degrees cooler than before. I finally put a small load on the truck this weekend - towing about 4,000 lbs. Heading up a fairly steep grade, the transmission temperature never exceeded the engine temperature - which was 210F max. It appears the cooling issue may be resolved.

Unfortunately, towing up the steep grade also included a new high pitched whine that I had not heard before. I'm guessing the trans got hurt when it got hot before.

Thanks for updating! Is the trans. temp gauge sender in the pan?

I use an Edge for my gauges - plugged into the OBD II port. I think its reading the temp from the factory temperature/pressure sensor.

My guess is that your noise was there before, but now you're just more sensitive to maybe something going wrong. Turn up the radio

One last follow up after some more towing.

The transmission seems to run 10 to 20 degrees cooler and I'm thinking it may be due to the new deep trans pan (Mag Hytech part 727-DD).

The whine I was hearing was solved by adding a few turns to the clamps holding the tubes on the intercooler. I guess I was hearing fleeing boost.