man that really sux. I know how frustrating it is to finish a project then find out you have to get back in there for something. The old 2 steps forward, one step back thing. Hopefully it's just a simple oversight and you get it fixed withought a headache.
So, will the tranny not engage drive? or is it like it's locked up?
I think you probably know more than anyone on here about the auto trannys...hopefully someone can help you. Would the TCU have anything to do with the issue?
One thing i do recall from swapping the ATX in my LeBaron, those torque converters are tricky. It can feel like it's all the way on there, but theres a key so that it will only seat properly in one specific position. I know you probably know that already, but just trying to help with what little knowledge i have
