I recently posted a topic similar to yours at the following link:
http://www.peachparts.com/shopforum/showthread.php?threadid=34620&highlight=126+harsh+shift

There is an explaination of where the vacuum modulator for the tranny resides. Good luck. Having mine adjusted/played with this Friday.

__________________
Chris

'04 ML500 - 53k, Inspiration Edition, Desert Silver
'11 Audi A4 Avant - Brilliant Black
'87 300SDL sold
'99 C280 Sport sold
'85 190E 2.3 sold