i recently did an engine swap which i thought went pretty well, until i found that the transmission isn't working.

i pulled it out still attached to the engine since i was reattaching it to the new engine and it is easier to just remove or reinstall with them together
the only fluid that leaked out is what came out from removing the axle and radiator
i'm planning to do a flush soon, so i didn't drain it all out
removed the tq converter from the old engine and attached to the new (i intentionally left fluid in the tq converter)
lined up the new engine and trans and guided the trans onto the engine slowly and carefully, it looks like it can't go on the wrong way as the shaft is notched on the sides.
bolted atx and engine together and dropped them in
put the axles back in, connected atx to radiator lines and all electrical connectors

i added 2 quarts of fluid as soon as i got it back in before starting it
after starting, ran through gears and added another quart or two
it's now reading full, but still not working

there is a faint buzzing sound (sounds electrical to me) when it's in any gear except for park or neutral

i'm hoping theres something just not connected or loose somewhere
i already checked all connectors on the trans and the entire engine bay for that matter. nothing unaccounted for

any ideas? what should i check first?

thanks