I got this car as a throw in to a multi car deal. It hase 104k miles and now I'm the 2nd owner. I got it from a VW garage that diagnosed it has having bad tranny with the torque converter code coming up, it also leaked transmission fluid. I haven't scanned it yet but it will start and drive. It feels like it is moving w the emergency brake on and the tranny will overheat after a short drive.

How can I be certain that I need a new torque converter/ tranny? Can I use a transmission from a compatible year 1.8T as long as I get the transmission module (cpu) from the old car? How can I be sure that a used tranny is any good?

Everything else on the car is solid.