Originally Posted by junqueyardjim

Rebreath- It is a difficult question. Automatic transmissions always have been and I think always will be difficult to work on. I know a good many qualified mechanics that just won't mess with them. And I think most of the people on this forum are not qualified mechanics, and so answers can be hard to come by. But really friend, did you search the archives at all for an answer. There is so much to that vacuum system that we just don't see at first. And so much has been written in the past by members who I feel have become tired of answering questions. So I did a quick search in the search box on "transmission vacuum adjustments" and I came up with a huge list of them. Here is one that might really be worthy of a good read for you. I read it through a year or so ago and made a good mental note of where I could find it when I needed it, and so I will pass it on too you. This member, Samuel R. Ross, has really gone through this vacuum set up. Here is the thread, and I would think that if you follow it through you will solve your shifting problem. Best of luck in solving your problem. Remember," you'll catch a lot more flies with sugar then with vinegar".

http://www.peachparts.com/shopforum/showthread.php?t=158216&highlight=Transmission+vacuum+adjust