Trans rattle sound on start up.

[Wparker85]

So i had my trans replace a few months ago due to a bad 3rd gear. ever since then ive noticed that on start up the trans/motor seems to rattle or at least make some sort of movement. I was just wondering if any one else is experiencing this. Dealer says everything is tight but idk. I kind of feel uneasy when they say they do a full inspection but they fill out the inspection sheet in front of me after delivery of my car after an oil change (dunno). So just wondering if im the only one hearing this or if its a common thing, i dont remember it doing this when i bought it. Im just kind of wondering if the mounts are on pivots that let it move and its just done this the whole time, but i just now realized it. Please guys let me know!!