98 4.0 Trans. Trouble

About 1500 miles ago i had my transmission completely rebuilt by someone that has done plenty of reputable transmission work for me in the past. A few days ago my wife was driving the vehicle and basically, the transmission overheated and fluid overflowed through the dipstick tube. She was smart enough to stop immediately. The fluid doesn't smell burnt and when you check the dipstick you can't even tell much leaked out. What could cause this? I know lately i've had a problem with some shifting occasionally. Every now and then when i put it in OD, it immediately goes into that gear instead of working its way up from a dead stop. I've been told that is the throttle position sensor. Could this cause my transmission to overheat also? Thanks in advance for any help.

Nick

is beter you scann and it give you the the necesary code