Ball joint nut won't tighten

Hi all,

After successfully removing the lower arm ball joint and replacing the front axle, I could not tighten the castle nut back on the lower arm ball joint shaft because the shaft rotates with the nut whenever I try to tighten it. There is really no place to hold the ball joint shaft! Any suggestions? Did I somehow damage the ball joint when removing it or is it just supposed to able to rotate by itself? (The removal is pretty smooth with a the ball joint remover.)
The car is still hanging there:(

Thank you!
By the way, my hydraulic floor jack is leaking oil and lowers itself slowly. Is this problem easy to fix myself?

you may have "mushroomed" the ball joint stud slightly with the remover.... try running a tap over the stud threads and a die through the nut... next time, loosen the nut, then smack the steering knuckle where the stud comes through with a hammer a few times. it should pop right out without the use of a puller

you will have to put pressure on the joint to keep it from turning. Take a block of wood and put it between your inner fender and your upper control arm and put a jack under your lower one and jack it up till it has the weight on the car on it, you should then be able to put the nut on and tighten it without a problem.

After you make sure the threads are OK, I just use a block of wood to pound the ball joint's taper into the hole. That usually holds it pretty firm for you.

If you do all of this and your ball joint is still too loose to hold on, its definitely time for a new ball joint, especially since its already apart.

Thank you very much guys!
Your input helped me out and made me my day!
mazdatech177 was right, I somehow "mushroomed" the shaft when removing the ball joint using that stupid ball joint remover and the nut would not go up at the point of "mushroom". I tried to run the die over the shaft, but the ball still rotates when I got the mushroom point. After removing the shaft from the hole, luckily the shaft is long enough to fit in a plier to hold it and the die went all the way up afterwards. After that the nut went smoothly and the axle is installed finally.
I deeply appreciate the helpful atmosphere of this forum!

no prob buddy, dont worry... you aint the first and certainly not the last to do that ;)