They no longer make the original two posts that hold the captive ball. You have to step up to a 10-32 post and drill out the pf just a little bit. Here is the closest replacement post I could find:
http://www.pinballlife.com/index.php?p=product&id=323
I used a 13/64 drill bit to open up the hole for the posts to fit. It is a good upgrade, they stopped making the original posts because they would break (that's what had happened to mine).
The picture shows the upgraded posts in place. They are the two on either side of the ramp. There's very little difference looking at them from the top side, but they are much thicker.
Post edited by Player1: Added picture.
IMG_3954.JPG