What could happen with a loose torque converter?

If the torque converter is loose it can do alot of damage to the transmission too. My ex- had to replace the transmission because the bolts were not put in correctly when someone else had changed something out. He had to put in a new transmission and torque converter. If it is running too rough you may have to change it all out. Check the bolts first to make sure everything is tight. If it is then you'll probably need new trany and torque converter.