Any experts know what this part is????

I am a newbie to this forum, and am looking for answers.... I have searched everywhere and been thru a couple forums already, so here is my question... I have a 1996 Chevy and am having trouble placing a part... I am currently rebuilding the tranny (4L60E) and cannot for the life of me figure out where one part goes... I have reason to believe it goes in the spacer for the valve body because I chatted with a guy on bowtieoverdrives.com, and he said it may be a block-off plug of somesort in the spacer plate... here is a link to the pic.... please help!!!!!!!!!

http://i156.photobucket.com/albums/t9/chevytrucksinmud/sparepart.jpg

Any help would be appreciated... maybe a diagram, or if someone knows the proper placement for this... I am sure someone has taken the valvebody off a 4l60E and seen this part and have the same probs.... thanks gang for any help....

It's a thigamabob and it goes in the duhicky.

Just kidding!

Good luck

It's a ball bearing or a butt plug. Or neither. Does that narrow it down for ya? J/K