Yes, it's called the Control Pressure Cable or Bowdin (sp) cable.
I can send you the PDF file on Monday (it's on my computer @ work). The file is too big to be attached to a message here, so you'll have to send me an e-mail, then I'll reply back with the attachement.
Keep in mind that adjusting this also changes your shift points. So you can have late/hard shifts (more aggressive), or early/soft shifts (more relaxed). But shift-points and shift-harshness are not independently adjustable -- you have to find a compromise.
Do a search here on the subject. There's lots of good info.
Jeff Pierce
jpierce@mpbc.org