Originally Posted by Marc7200

This happened to me after I changed the cables on my bike. After messing with it for a few weeks I discovered that I installed the cable clamp tabbed washer in the wrong position. The tab on the washer hit the derailleur hanger preventing the RD from moving all the way to the right. Check the attached tech doc under the Stroke adjustment and cable securing section. Refer to the illustration under step 2 where it says make sure the cable is securely in the groove. Make sure the washer with the tab is in the right position.

HTH and good luck.

http://techdocs.shimano.com/media/te...9830612494.pdf