I'm trying to replace my front lower control arms. I recently had the stock bolts replaced with the 9/16 bolts, maybe about a year ago. I'm using a Kobalt corded impact wrench that says it can handle 350 ft lbs forward and reverse. The nut and bolt don't look rusted. The bolt spins so I know it isn't rusted to the mount. I'm not sure what else to do since I'm already using an impact wrench.