04maximas

So I just replaced my crank angle position sensor today hears where I'm confused. The one I removed was like stuck to the block after I took the bolt out I had to pull kinda hard and it had no seal. When I installed the new one it kinda just fell right in and had alot of play like I could flop it around but when I installed the bolt all was tight. Is that normal? Engine started fine and no signs of oil leak also I did feel around inside for the old seal I could not find it