These nylon pieces fit into a notch on the shaft with the lock ring on it.
This shaft fits into the shift tube. The shaft also has slots machined into
it to fit these nylon pieces.
A couple more pictures. Finally getting better at attaching pictures. LOL
Yep, that is the main shaft.
Those two nylon peices keep the colum from collapsing, but are designed to break and collapse the column during an accident/ impact.
There nylon is injected in the shaft when assembly. You will have to come up with something to inject into the spaces if you want to fix it. Some guys will say, to leave it and put it back in the car, as it will not move once it it is installed (but I would fix it if it were me).
Good luck,
Jason