Dirty throttle body?
 

Quick question, I hope it's not a stupid question.
My question is what does a dirty throttle body have to do with the transmission not shifting right. Someone told me to clean up the throttle body before I move on to replacing the transmission.
I wish Tech was still around to help me with this.
Thank you for your help.

If it was so dirty to effect engine RPM like surging, then maybe, if it`s running good then don`t bother cleaning. Basically you are right that it would not effect transmission shifting.

The idle is erratic and it does surge up and down and sometimes it stalls, after driving and putting it in park it really surges. I'm pretty sure it needs cleaned but still don't understand why that would screw with the transmission. I can understand it would cause it to idle rough . But since cleaning up the throttle body is cheaper than a transmission I guess I have nothing to lose. Thank you.

Clean it. But for the most part you are correct in that it`s not going to effect the transmission. As always do the cheapest thing first.