Here is a common issue.

You remove the valve body, and a small metal pin falls out of the transmission.

But you can't find where it came from.

The attached pictures show where it came from..

The part is a DETENT PLATE LEAF SPRING PIN = it prevents the spring arm from rotating on the single mounting bolt..

PIN, DETENT PLATE LEAF SPRING
MB Part# 126 991 03 10
Application: All 722.xxx transmission.

Attached Thumbnails

     

THANK YOU..THANK YOU...THANK YOU.. that pin somehow got in the valve body...(did not rebuild)..when I turned the valve body over the pin fell out...I stared at that valve body for 2 hours trying to figure out where it fell out of... googled it...and you popped up.... Man, thanks again

Glad it helped you.

Hi,

As you are working with the same tranny and valve body, would you check my question on this forum?

You can find it :
http://www.peachparts.com/shopforum/showthread.php?t=302632

Maybe you are familiar with it? thanks!