I'm trying to replace my rear upper control arm on an 04 coupe. The ball joint nut on both sides isn't moving even with a good sized air gun pounding on it. The cotter pin is out. There is no rust or corrosion that I can see.

This nut has never been removed, so it's been in place for 18 years. The original torque on this is only 62 lb-ft. All the other bolts in the suspension have moved without a problem.

Any ideas how to get this nut to move?

 

PB Blaster and a breaker bar. Make sure you're using a 6 point socket so you don't round off the edges with a 12pt.