SMartin,
From my experience the book says to remove slack for a starting point, but that point is hard to find because of the rubber boot on the end of the cable. there is no firm resistance when the slack is out. I looked at the end of the arm where the cable attaches and noted when it started to move and when it quit moving. On my 300D there is a lot of difference in just a few turns from this point. in one direction it shifts so quick thru the gears that you have no acceleration and the other way it never will shift into 4th. I have spent a few hours going from one parking lot to another adjusting it at each stop. Just trial and error. Hope this helps. Lee