Lower Control Arm ball joint bolt seized

[CrimsonEclipse]

Trying to replace the lower control arms on a 2011 Yaris.

The bolt that attaches the control arm to the bearing assembly (locked with a cotter pin (which was removed)) spins without loosening. I placed a jack under the ball joint and added pressure but it wasn't enough.

Can I use a pair of vice grips through the ball joint boot and clamp down long enough to break the threads loose

Note, I am using thread oil to possible loosen up the threads

I am replacing the lower control arms because the rubber around the rear bolt is cracking and possibly failing.