Quoted from Audioenslaved:
On further inspection the trap door is actually missing the flap! So off to buy a new one. I’m guessing the trap door is meant to sit proud of the playfield and the flap takes up the slack. I can see why the flaps would continue to break toowitb the ramp sitting too close to the playfield
I was dealing with this a few weeks back after recieving a replacement flap trap door from JJP. After replacing I noticed it was hitting the wireform ramp above it when the coil fully extended. Fellow pinsiders mentioned and linked guidence for me about this issue, so I proceeded to test the various ways to stop this from happening again.
My sweet spot landed on just using 2 #8 washers that I super glued together then dropping them in the coil sleeve, while making sure it was laying flat when put back together. I tried nuts, more washers, less washers, adding spacers to the coil assembly but for my machine just the 2 washers has been great.