I have a rattle that is worse in park or neutral that is coming from bell housing area, I took inspection plate off and its louder. I didn't know if maybe had cracked flex plate?

 

Flex plates have been known to crack, If it quiets down in gear then most likely flex plate. Also check crankshaft end play, worn out thrust bearing will allow crankshaft to walk back and forth, allowing torque converter bolts to hit housing.