Yes, original T-Case. The onlything I replaced was a radiator and a starter around 190,000 miles. If you take care of stuff it will last you many good years. The T-Case was needing an overhaul when I sold it, but was still extremely reliable, it never let me down no matter where I took it.
Full time 4WD causes issues when people neglect the systems. I was very religious about maintenance and every fluid was changed at least once a year, regardless of mileage which included the transfer case which many people often overlook. At 230k+ miles it was due for an overhaul but the current owner says he has no issues with driving it, just won't stay in 4Lo due to a linkage adjustment but who needs 4Lo anyhow LOL. I made a few trips to California and back in it, a trip to Washington, and all around Idaho in the mountains and trails with it and never had a problem with it. The majority of issues you hear of, the person having the problems doesn't exactly tell you what kind of abuse and lack of maintenance they've put it through. If you stick with the selec-trac 4WD systems in the jeeps you won't be sorry, the full time 4WD systems were great, except they would rob you of a little bit of overall power, but in snow/ice they would completely blow you away with what it could do. Wish I had a video camera of my test with an atv trailer and an ice covered hill. I stopped going up the hill about 1/2 way, with the loaded trailer and camping gear, and thought what the hell lets see what it can really do, even with mostly worn out tires it managed to make it up that hill from a dead stop, well kind of sliding backwards as it was that icy. Just because it doesn't say Ford on it, don't think its not extremely capable, reliable, and rugged. I wouldn't want to try driving the trails I took my jeep on in an explorer LOL.