When brush cutting, the adjustable top link tends to gradually unwind (i.e., lengthen), and therefore the angle of the brush cutter changes. I start off with the brush cutter about level, and end up with it canted up in the front. That means the rear wheel digs in when I turn quickly, and I can't raise the brush cutter over a low obstacle (like a tree stump). Annoying. It doesn't happen with my box blade, so I assume it's vibration related. It didn't happen for the first ? 300 hours of tractor use, so I also assume there's a wear factor. So, I could use a chain instead of an adjustable top link, buy a new (and presumably stiffer) adjustable link, install a hydraulic top link (I'd rather not "plumb" for new hydraulics), or just stop greasing the current link. Any other ideas? Does someone sell an adjustable top link that has a tightening sleeve to prevent unwanted turning?