cccp

Hi all been a long time since i posted here but dont know where else to turn for help this is the scenerio.... i bought a 2008 toyota tundra 5.7l v8 with a seized engine. When pulling the motor out i could not turn it to get to torque converter bolts so i pulled the engine with the torque converter bolted to the engine. After i had the old motor out i pulled the pan and was able to turn it the motor over to get the torque converter bolts out. The first time i stabbed the trans in it seemed like i dint have the torque converter in all the way in the trans so it pushed up on the flywheel and the flywheel pushed up on the bell housing i noticed that when i was trying to spin the motor to put the torque converter bolts in i could not spin the motor over. Pulled trans out again and messed with the torque converter and what appeared to me got the torque converter to go in all the way. Stabbed the trans in the 2nd time and everything seems to be right. After all and done the truck starts and runs so on the first test drive i put the engine under a load and it died. pulled in it scan for codes the code came up for crank sensor. pulled the crank sensor out and it looked like it was damaged. i thought maybe it got damaged from being shipped or something like that. had a spare sensor put it in the truck starts and runs no noise coming from trans. Take it on a test drive the trans shift like its suppose to so i put the engine under load and hear a snapping sound and truck dies. Same code same scenario. The crank shaft position sensor cracked in half. Started to pull the trans out. The torque converter bolts are all damaged like they were hitting the bell housing and two of the six are loose. I know i torqued them to spec. the trans is now sitting on a bench. there is damage on the engine side where the toner ring and the flywheel spin on the bell housing. I am at a loss at the moment and don't really know what to look for or do. So any help with this subject matter is really appreciated