Hi everyone, I'm new here but have been working on fords for 20 plus years. I am rebuilding my first 4r100 for a friend and we used a transstar performance friction kit and gaskets and their triple disc converter. We also installed a complete tugger kit. The transmission will not move in any gear. We checked pressures and they are over what the atsg book specs are. We have double checked all check balls and roller clutches. The transfer case is ok. I don't get any oss readings. I've tried 4x4 low and high. I've done the air pressure check on all the clutch packs and no leaks and everything engages. Before we rebuilt it he heard a loud bang during a launch then nothing it wouldn't move. We found lots of metal in the pan on tear down but nothing broke that we could see other than over heated frictions. I'm not sure what I've missed but something isn't right. When we've had the trans out after the rebuild there hasn't been any metal other than light gray on the magnet. We also installed a mishimoto 6.0 cooler and flushed out the radiator and lines. Any help or suggestions are appreciated! Thank you