little help please

If the pins are sheared, the shaft will likely fall out, or at least move easily up and down inside the tube; there is nothing else holding it in there, except perhaps a little oxidation.
If it falls out, simply stick it back in.
The coupler,on the end, is supposed to be pinned to the steering box. But if the coupler has been disassembled for cleaning and repacking, it is quite difficult to successfully reassemble. Normally this is not a big deal. But if the nylon pins are sheared,the shaft could migrate out of the coupler;only gravity would be keeping it in there.