Here’s a Tip from a Top Mechanic

Over many years of removing seized, corroded, and galled fasteners, I have found the best solution is a 50% to 50% combination of Dextron III ATF and Stoddard solvent. This will easily out perform anything you can purchase in a spray can (Kroil, LPS, Blaster, etc etc). And it’s not just a little better, it is a lot better. Put the solution in something you can drip it out of, like an old school oil pump tin. A few drops on the plug when it is as lose as you can get it, then snug it back in. Back out, lube, back in. It can take some time, but it will much less time and money than the alternative.

Ray