Are you just whacking the knuckle with hammers? For this to work you must smack the top of the knuckle at the same time on opposite sides right where the balljoint goes into it. It might take a few whacks to get your timing figured out but if you do hit both sides at the same time it should go eventually. If that doest work try some larger hammers.

I've had balljoints and tierods stuck to the point where a pickle fork wont do anything and beating on it even after torching it with map gas wont work. The double hammer trick almost always works for me but every situation is different.

 

I didn't try double hammers, but I beat on it all around the joint. I don't have a small sledge, so I gave it some love taps with the 20 lb sledge.

I'll try the double hammer trick and see if it works. If it does, I can return my pitman arm puller.

 

I feel your pain my brother. I had the exact same problem, damn cv axle stuck on that stub shaft.

 

Seriously........ Soak and better soak with a releaser, then put the stub axle nut back on almost flush, then whack the s*** out of it with a BFH.
Worked for me. The nuts threads will damage way before the cv shaft ones. Especially as the force will be dissipated across the whole of the nut, if mounted almost flush with the end of the cv shaft.
A new hub nut will be all you will need after this.
Al.

 

I'm making a note here: huge success.

A few tips/notes that I want to add here for searching purposes.

There are no short cuts, you have to remove the upper ball joint from the knuckle to get enough room to the hub mounting bolts.

No amount of hammering would free up my ball joints. My knuckle is now dinged all the hell from hitting it so much. Go buy/rent a pitman arm puller to make short work of popping the joint free. I had to grind a 1/4 point off my pitman arm puller to make it fit.

You'll need lots of penetrating oil. I probably used a half a can of PB Blaster.

Buy new hub bolts so you can use the old ones to help hammer the hub free.

Be prepared to remove the whole axle to make room to clean the knuckle. My knuckle was so corroded in and around the hub mating surface, it took an extra 30-45 minutes just to get it all clean and flat. I didn't want to work around the axle half sitting in there.

I used an old trick to remove rusted on rotors to quickly break the hub loose (pic attached). For this, I used two grade 8 bolts and 4 nuts. The idea is that you thread a nut to the inside of the caliper mount, and one nut on the end of the bolt. The nut on the end of the bolt really just protects the bolt. I also use an old pair of brake pads to help make up the distance and prevent gouges in the rotor. Put a wrench on the head of the bolt and one on the nut against the knuckle. As you tighten the nut, the bolt will push out. This works great for popping off stuck rotors, and in this case, stuck hubs. I put the rotor back on with two lug nuts to keep it in place. Keep alternating on the top and bottom bolt to keep the pressure even. Once I had a lot of tension on the bolts, I partially threaded two of the old hub bolts (closest to the side I was working on) back in. It only took about two good whacks on each hub bolt to pop it completely out. To be fair, I had used a lot of PB Blaster and already tried pounding on the hub bolts to get it out. I'd go back to this method of getting rotors off if I had to do it again.

 

I had to whack the sh*t out of those rear rotors the 1st time (about 90K).. I made sure I greased the mating surfaces. 2nd time just came off no effort (about 180K).