If the vehicle has a quick steering extension on the pitman arm, once you remove it, you MUST get the front end aligned. If I remember correctly, you have to lengthen the tie rods to make them fit the extension. Once you try to reassemble the tie rods, your front toe is WAY OFF.
Typically a link/king pin setup gets sloppy, not tight as is the case of a bad ball joint. Both seem to get sloppy and loose. Another problem could be a bent spindle, a bad bearing in the steering column, or something rubbing against the steering rod as it exits the steering column causing undue friction.
From the brief description, it sounds like what I posted 2 above this entry. I've had several instances where the steering box has shifted and binds similar to what was explained by the original author.
But, it's mechanical and unless I can see and feel the problem, all I'm doing is guessing.