The factory bushings on the axle end of my front upper control arms were starting to show signs wear and were a bit sloppy. So I replaced them with the Currie Front Axle Johnny Joint Kit
The instructions are very clear and detailed, so I won't go through every step, but you will need to cut and weld.
I did one side at a time and started on the passenger side.
After measuring and marking, the top half of the factory side mount was removed with a sawzall very easily.
The new Johhny joint mount fit perfectly into the lower half of the factory mount.
It was welded in place around the top and with three rosettes. An inch or so was welded at a time to prevent overheating the joint. It's a little tricky for an amateur welder like me to weld in the confined space.
The driver side factory bushing did not want to come out easily, so I removed it in pieces.
It took a little pounding with the provided tool and a hammer to get the Johnny joint mount in, but it went in easily enough. Once in, a couple of tack welds on the inside edge ensure it will not move.
Like I said, the instructions were very detailed and clearly written and easy to follow.
I can't say that I can feel any increase in vibration or road noise by having upper control arms with Johnny joints at either end.
They do help hold the front axle better, and when my tires get some imbalance from the Airsoft BB's it is far less noticeable.
They will also not bind like the factory bushings and should allow for more flex.
A very worthwhile and easy to do upgrade.