99 XJ, transmission, TCC, or trans modulator?

I have a 1999 Jeep XJ Classic, I just recently replaced the harmonic balancer. In doing so, I removed the radiator and trans cooler in order to make room for working. I had to cut a trans line because I couldn't remove the clip. A small amount of trans fluid spilled out, it seemed a superficial amount (not even half a cup), so I patched the line when I was finished with my repair. The patch is holding (no leaks), but ever since I finished installation of the harmonic balancer, my transmission doesn't seem to want to stay in overdrive. Sometimes it will, but other times it just goes in and out of overdrive while i'm driving. Im thinking it could be the torque converter, or maybe the transmission modulator, but i cant be sure. My trans fluid level seems fine. Please help!

Well, no vacuum modulator on the AW4.

TPS: you can check it with a multimeter, if out of spec has to be replaced.
Throttle pressure cable: you can adjust it. http://naxja.org/forum/showthread.php?t=1015963

NSS: more than just a neutral safety switch. http://www.jpmagazine.com/techartic...eep_cherokee_neutral_safety_switch/index.html

Brake switch: when the brake is depressed the torque converter unlocks.

If the problem was the TCU fuse or the TCU I would expect more symptoms with the AW4 than what you are experiencing.

thanks for the assist...never figured it may have been the NSS...looks like a pain to install though...oh well, better get crackin'