My 69 C10 shift linkage locks up sometimes

[data89]

I have a 69 C10, 3 on the tree. Occasionally, whether downshifting or upshifting, my linkage will lockup (naturally only at a stop with vehicles behind me), and I have to turn off the engine, get out, raise the hood and pull up one of the 2 linkages on the column. If I'm attentive to shifting, I can go months without this happening, but, sometimes I just want to shift without babying it. It's always been a little stiff going from gear to gear, but, I think this is not normal, duh. And there should be a procedure for adjusting this, right?