I want to remove the stock upper track bar bracket.

The rear bottom bolt is threaded into a round "nut" that looks like a spacer.

It just spins. I can't feel any broken welds so i don't know why it wouldn't spin. It seems like it is hardened since I can't get vise grips to get any traction on it.

I might able to tack weld the sleeve so it can't spin. It is soaked with kroil and awkward to get at though.

Or I can probably grind off the bolt head and knock it through but it isn't all that accessible so it would take a while.

Is there trick to this?

All of the other captive nuts have flats....

 

I put vise grips on it and took the bolt out. Not that hard to do. If your vise grips can't grip it then u got a cheap pair

 

I had to tack mine to the unibody rail.

 

I ended up grinding a flat on it and holding it with a Craftsman "clench wrench" that has been lurking, unused in my tool chest for a decade (one of those Christmas gifts you get from people who know a tool might be a good gift but know clue as to which one....)

The nut looks like it was electro-welded to the bracket. I suspect that vise grips are a real long shot if the bolt is frozen enough to break the nut free.