It's a press fit with a catch.

There is a little lip machined into the clutch that that ball snaps over. I used to cuss taking the uniballs off. Now it's easy because I just use the heat of a small soldering iron to cut a groove in the ball. You don't even have to go all the way through. Just make a cut deep enough to insert a screwdriver blade and twist; the plastic is pretty brittle.

I make it a practice to replace the ball whenever the wear line on the ball is over a mm or few wide. That ball is critical to having the clutch run concentric with the fan. Gordie is surely correct; it isn't worth the cost savings to skip replacement when it's needed.

Ben Minor