The type of noise you describe makes it hard for me to visualize anything INSIDE the trans which could make that kind of noise..
but if the driveshaft rubber flex joint is letting the driveshaft swing out enough to hit the bottom of the car it would sound like that....
ANYWAY ... others have posted pictures of the front destroying the INSIDE of the car...so try looking there...

It may not happen at hand turning speed because it is the result of centrifugal force...