Originally Posted by Russ Roth

I seem to be missing where the problem is, the threads in the crank look like they're in perfect condition. So make sure the center post of the tool is fully recessed into the tool and tighten the tool into the crank. Go by hand first to make sure you line up the threads right and you should be able to turn it in by hand most of the way. Use your wrench to snug it down and then start turning the center post to pull the crank off. Cranks are a wedged fit which makes them really tight and often it feels like the threads are going to strip out. But if you have the center of the tool fully recessed when screwing in and screw the tool into the crank all the way, unless the tool really sucks the crank will just come off. Might have to really hang onto the crank though. Usually I do the non-drive side first so I can use the drive side as leverage. That lets me do the drive side using the drivetrain as the leverage which can be necessary with how tight things can be.