The steering bellcrank pivot shaft is secured to the crossmember bracket by a tapered pin.  If that pin were to work loose, the entire bellcrank could drop off.  That would be a VeryBadThing(tm).  Even if the tapered pin didn't fall out completely, it can allow a lot of slop in the steering if loose.

Willys offered a replacement  tapered pin designed for rough service.  A nut threaded on the end so it couldn't back out.  I couldn't find one of these threaded pins, so I made my own.  To say the pin is tapered is a bit misleading.  It is a constant diameter, but has a sloping flat surface milled on one side.  As the pin is inserted, the taper of the flat surface locks against the pivot shaft.  I started with an appropriate sized fine-thread bolt and cut off the head.  I machined the taper, but a grinder or file would work fine if careful.  Here is a glorious Cheese-O-Vision comparison of the two pins.  Note how the threads are only on the end:

 

Here is a view from underneath showing the threaded pin installed:

Removal of the original pin can be tricky.  The pin could have been inserted from either side.  I don't know which direction was original from the factory, and this may have changed during production for whatever reason.  Furthermore, if the pin was removed anytime since then, it may have been reinstalled from the opposite direction.  Try to move the pin in either direction with a few light love taps from a hammer and brass punch.  If it won't budge, carefully examine both ends of the pin to determine which way the taper slopes before bringing out the heavy artillery.  A small inspection mirror and bright flashlight will be needed, but even then it is difficult to determine which way the pin faces.