northernroots

I have seen a few other threads that talk some of this, but not exactly. I have a 1995 ZJ with 240k miles. The transmission was rebuilt at about 100k (was my parents back in the day). It has an issue where when it is cold out, below 40-50 degrees typically, it will be locked in 3rd gear and the OD light will be on signifying it overdrive is off. I can shift manually fine, but when stopped at a sign or light, have to shift back into park and then back into first gear, and again will shift up to 2nd then third but not overdrive. after about 5-10 minutes, i am assuming once the transmission is warmed up, if I turn the jeep off and start it back up, it will be fine, OD light off and will start in first gear like normal and typically be find the rest of the day. Fluid level is good, but that is the extent of looking at anything at the moment. Any thoughts on where to start?