a little update. i changed the diff oil today. im almost positive it was the factory fill, as it didnt apear to have been unbolted before. but its possible. it was a medium brown color and the magnetic plug didn't have a lot of metal, that made me feel better about it. i used Valvoline Synpower 75W90, as it was available local today at autozone. i bought and extra bottle and i will change it again in 10k miles or so. maybe after that i will switch to Amsoil 75w110. i figure the synpower should stay in grade for 10k miles. i do 90% highway cruising, not tracking or racing ect. i reused the washers, just flipped them over, it seemed to tighten down well and seal good. i took it for a drive and all seemed just as quiet as before. ill double check in the morning to make sure i have no leaks.
tomorrow i plan to call the Honda dealer to see if they have any MTF in stock. if not i will just order some Amsoil. the shifting is slightly notchy when cold, and at random times. when its warm it usually shifts fairly smooth, but i plan to change the diff and tranny fluid every 10-15k from here on out.