I have some questions I need answered in my quest to understand the AT world. Is the TC in a '98 3800 II (4T65E) vehicle able to lock? I would assume so and if so at what times does it lock. Also at what temperature does the AT fluid or engine coolant need to be to satisfy the trans computer into allowing it to lock? Does anyone (has anyone) manually lock or unlock their torque converter because I've read bad things about that?