NV3550 overheating?!

I recently replaced my clutch on the 2001 XJ, never really noticed any heat issues before. I recall the driveline being warm, but not crazy hot. Anyways, I dropped the driveline, replaced clutch, put new fluids in both transmission and transfer case. I've ran Redline oil for the life the vehicle, never any problems. MTL in the 3550, high-temp ATF in the transfer case. My first day back to work, I checked underneath the jeep after my 1 hour commute to work. Transfer case and transmission were EXTREMELY hot to the touch and would burn my finger if I left it in any one spot for more than a second.

I also started to notice I can feel heat (more than usual) radiating from below the console / shifter area. Both of my shifters also become hot after 30 minutes of driving. Checked fluids, they are fine. Shifts fine too, no weird noises or leaks to report either. It isn't the engine, running like a top with no cooling issues. Bottom of oil pan / bell housing is hot but not unbearable. Transmission and transfer case is damn HOT.

This is driving me nuts, can't figure out why so much heat. It has to be the transmission, I just checked the temperature after letting it sit for four hours. Everything is cold except the transmission which is still pretty warm to the touch. Granted the transmission has 210k miles on it, but I can't figure out why all of a sudden it is doing this. Any ideas? I'm stumped.

It may be relevant, it may not, but I had a issue where my transfer wasn't shifting into 2X (the shift lights were lying to me). I never really noticed (I was driving the interstate) until I stopped and heard the water dripping off the bottom of the Jeep onto the transfer and it turned to steam. Made a noise like dripping water onto a hot skillet.

Transmissions getting hot enough to burn a finger can be normal, 180-200 F isn't unusual. Cooked meat is typically around 160 F in the center.

What is your CAT doing, when they go bad or the fuel ratio in your motor gets screwed up they can get red hot and generate a bunch of heat, enough to melt carpet on occasion.

All transfer case ranges working normally. Good idea about the cat, it is over 8 years old. It was one of those hiflow aftermarket ones. I down pipe that feeds it crosses right by the transmission too.