is the tcc lock up just a sensor that your have to replace on the outside of the tranny? or do you have to take your tranny out to fix it?

On the 3sp, TH125C/3T40 it's located under the valve body cover on the Driver's side of the transmission. I listed a brief description on how to get to the valve body here, near the bottom of the thread. Depending upon which version you have, there are one or two sensors that detect what gear you are in and the line pressure, that control just when the TCC solenoid will engage.

If it's the 4sp, 4T40E, then I'd have to look it up.