Just was wondering if this is normal with my freshly rebuilt 4L80e?
If I turn the output shaft either way in any gear, neither of the front shafts move at all. Same goes with the front shafts, by rotating the smaller diameter input shaft it does not make the output shaft rotate. The trans is a fresh rebuild and is bone dry.. however a buddy of mine has a th400 and I shifted it into gear (its out of the truck, fresh rebuild also) and rotated the output shaft and it made the smaller diameter input shaft start rotating??? I shot a video
https://youtu.be/hIk8NODmCqs

 

There is no fluid pressure being directed to any clutch pistons to engage clutch packs and lock various components together.