1994 Explorer ....

Had been getting progressively more loose ... replaced upper and lower ball joints last year and had not driven much since then ... guess with bad ball joints it wasn't as noticeable?

Anyway, finally got the adjuster screw lock nut loosened ... if you are doing this, don't even try it without PB Blaster first - let it sit for an hour, then use a medium length extention that allows you to use a ratchet between the pump pulley and the fan blades - long ones are too long and short, too short.

Anyway, note which way the screw slot is facing so when the nut does break loose, you can tell how far it moved CCW. I was able to move the input shaft back and forth with my hand while I turned adjustment screw clockwise - you can feel the slack being taken up. At one point, further screw adjustment CW, does not seem to reduce movement in the input shaft ... for mine, a half turn appeared to be where play was gone ... further adjustment did not tighten it further, so I put it back together and test drove.

As other posts note, if you have gone too far, the steering will start to bind and not self center when you exit turns. I am assuming this level of overtight will cause the gears to wear very quickly - not to mention being dangerous!