tkcutlass

Not sure how/why the upper ball joint ended up with taller than usual castle nuts.
Trying to get a cotter pin in I think I over-tightened it.
I found a shorter castle nut and figured i'd break the spindle loose from the ball joint and reseat it with the new nut so it could be properly torqued.
Now when attempting to tighten it the ball joint shaft spins.
I tried using a pry bar to create pressure on the shaft seems to tighten but once pressure is released the shaft spins easily if you try to tighten further.

matt69olds

Unless you torqued them ball joint stud enough to stretch it, I doubt you damaged anything.

If the ball joint is used and has some wear, it’s common for the stud to turn easily inside the joint. As a matter of fact, you can turn them when new, it just takes a little more effort.

I routinely position the cotter pin hole in a location that makes assembly and future maintenance easier.

Having said all this, if there is any doubt about the safety of the ball joint, replace it. Is your safety and your car worth less than the 30 bucks and couple hours time to replace it?