Originally Posted by
C2H5OH
That's what I thought when I first saw that axial bore. I further thought, that the bolt may slide into that fitting by installing a tool and pulling towards the center of the plug. However this is not compatible with the infos given by the 737 tech channel.
As said before this stub of the roller pin is rather short. I wonder if it is still blocked if wrong diameter locking bolts are used.
The roller pin cannot be any longer than the opening in the bottom of the guide allows for. Looking at the RH image, there is a significant bit of the roller pin inside the guide and the locking pin is centralised relative to the width of the opening at the bottom of the guide. I posed a question earlier on whether the roller pin could perhaps have moved past the locking pins with a bit of flexibility, but I cannot see that happening (based on these images), especially as it would mean both pins being too short and both sills moving outwards (in opposite direction).
Just a guess, but the hole in the centre of the roller pin may be for adjustment of this pin. It probably does not allow a bolt to be fitted in there. The suggestion earlier on of using this hole to lock the assembly would not allow for the same provisions for locking the bolt in place, would be more difficult to inspect and would put extra stresses on the roller pin mounting. The locking pin as it is used by Boeing here is a much simpler option as it prevents movement of the pin relative to the guide by blocking this guide, which is what is needed in this case.