I replaced my Galant tranny yesterday, the installilation was smooth. I start it up to test drive it and BAM....if you place the car in reverese the torque converter is fully locked and the car stalls, however through the forward gears its completely fine. But everytime you place it in reverese the torque converter is fully engaged and the car dies. Any ideas?

 

your fluid level is incorrect.
you must check it in neutral, NEVER in park.