Flat towed with tcase in gear, whats broke?

I ended up flat towing my jeep 20 miles with the np231 in 4 hi(i think the dog stepped on the lever while we were waiting for friends, I had already towed it 40 miles no problem). Aw4 was in neutral I now agree with those who say tranny in park. Smoke was coming out from under the hood, so I pulled over. Is it the tranny or the tcase that I broke? Front axle has hubs, and they were unlocked so should have only been the rear shaft turning. Everything seems to function, tcase in gear jeeps wont roll in any gear/park. Tcase in neutral jeep rolls in any gear. Jeep rolls with tranny in neutral and tcase in gear. Engine running jeep wont move under it's own power in any combination of gears. How do I diagnose what is broken?

You fried the tranny. By towing it with the tcase engaged you were spinning the tranny the whole time. The problem is that because the pump that circulates the fluid runs off the input instead of the output, there was no lubrication. Sorry. The only good thing is that used trannys are normally fairly cheap.

Kinda figured as much. Why doesn't towing a 2wd kill the tranny with the front wheels up?

you got lucky. i did that, and now my jeep looks like this:



just swap the trans, and enjoy your jeep some more!
and pull the damn driveshaft before towing!

At low speeds, for short distances, towing a 2WD will work without pulling the shaft. Long Distance towing, pull the rear shaft.

I remember towing a YJ over a few states. I was so paranoid, I pulled each shaft at the axle yokes and used bungees to hold the shafts up out of the way.