Functions as a ball joint (VW Jetta '09)
Its a ball joint alright.
In my case, it was much easier to go at the old one from the top nut first, and then the bottom 3. Helps keep pressure on the stud.
Speaking of the Stud, putting the new ball on, i had issues with the stud constantly and freely spinning as I was tightening the top locking nut. Theres a little indent in the top of the stud to place a 5mm hex bit. The idea is to hold that steady while using an 18mm wrench to tighten it- but you really have to remove the axle to have enough room.
In my case, i didnt want to take out the axle, and it resulted in REALLY congested working area. If i were to do it again, I would take out the axle.
If you're in the same boat and don't want to, I was able to bypass the issue by taking an angle grinder or hacksaw and shortening a 5mm hex wrench, JUST enough to feed it horizontally between the top of the stud and the bottom of the axle. See the picture attached.
Bottom Line Yes, I would recommend to a friend