I think the bolt fits snugly on purpose. This is a new ball joint with a new nut with perfect threads. I tried using the jack but that didn't work. I tried beating the hub with a sledgehammer to seat the rod in the ball joint but that didn't work.
Lastly I used the sledge with a piece of wood from the bottom of the ball joint and that seemed to seat the rod into the hub enough to where I could again start turning the nut until - bingo - she's tight.
I've had ten years of cursing at this old ball joint.
1999 I decided to replace the ball joint due to a torn boot. I proceeded to beat the living crap out of this joint with a pickle fork and sledge hammer. I beat it to death. I beat it till I was dead. I tried pullers, extractors, oils, you name it. I could not get this ball joint out, no way. I sat there and reasoned this exact thought. "It's not like this ball joint will ever see sand". So I called it a day. I'll live with it.
The next day, bored, I decided to drive to Lake Mead (I lived in Vegas). It was a nice day and upon getting to the lake I happened upon a huge dirt parking area which led almost to the lake. I drove up as far as I could but it got dicey. There were areas of sand and my Mirage had trouble with this. In fact it got stuck. I was stuck in the sand.. The harder I tried to extract myself, the deeper I got buried. In the end, my entire front end sat deep into the sand to the engine and body. I was in such disbelief I took a picture!
That ball joint with the torn boot I'd said would never see sand not 12 hours before? You couldn't see it because it was BURIED in sand. I couldn't have written this script. I eventually got pulled out by a tow truck. I never did replace that ball joint until just now. When I removed the A Arm guess what filtered out from the body support? You guessed it, Lake Mead sand, a whole pile of it on my garage floor.
True story.