1993 T100 4WD 5-speed with 13K (no, not 130K) miles. This weekend my wife and I took a trip with it, and at about the three-hour mark she took over driving. While riding along, I noticed that the transmission hump area (on top of the carpet) was very warm, though the floor pan areas on either side were not. The metal portion of the transfer case lever was so hot that I couldn't leave my fingers on it for more than a few seconds. The transmission shift lever was also warm, but not painfully so. Nothing seemed unusual about the way the pickup drove.

When we arrived, I waited a few hours for the truck to cool down and checked fluid levels in both the transmission and transfer case. Nothing wrong there. There's no reason to believe that the pickup was inadvertently shifted into 4WD (no indicator lit on the dash and the front driveshaft was free to turn by hand). However, my gas mileage was extremely low (14.8 mpg on the way out and 15.8 mpg on the way back). Normally I expect 20-21 mpg at 65-70 mph on the interstate.

Has anyone else experienced this, and is it abnormal? Since I drive the pickup alone 99% of the time and it rarely goes on a trip, I've never had reason to explore the temperatures of parts of the cab before. I have, however, noticed that the cab is always very warm and the a/c is needed on even fairly mild days to maintain a reasonable temperature. I attributed this to the exhaust crossover.