Yes that's the A arm with the Ball joint and bolt in the middle. There is 1 bolt at each end od that arm.
Those are the 2 bolts I'm talking about. That's how they disconnected the new axle I I got from the junkyard.
Each end of that A arm has 1 bolt that goes up into a bracket through an end of the A arm and into the metal below the floor.
It's there the bolt is spinning. They has to be a nut on the other end. I was thinking it was welded and broke loose. But the other sidea of the A arm did the same thing.