Don't use WD40 it's useless....
"I know from experience that this works. Soak everything with WD40 or something like it."No please don't use WD40 or "something like it" or you'll never get it off. WD40 is the biggest scam of a penetrating oil in existence. IT DOES NOT PENETRATE! If you want a true penetrating oil use PB Blaster, Thrust or Aero-Kroil http://www.kanolabs.com/Here's a direct quote from a guy that read one of my articles and took my advice about PB Blaster as opposed to WD40: "I knew where the cap and the locking nut were, I just couldn't budge them. Went out and bought PB Blaster. Ten minutes after spraying it broke loose. PBB rocks!"WARNING. WARNING, WARNING!!! Be very careful NOT to get PB Blaster near ANY engine or transmission seals. True penetrating oils will EAT engine seals causing catastrophic failure of that seal. The most common seal DIYers destroy is the transmission output shaft seal. Be very, very careful using PB Blaster on your engines coupling bolts and DO NOT use the spray feature when working that close to seals. If you need to use a penetrating oil on coupling bolts fill the PB Blaster cap with the penetrating oil and then use a Q-Tip to dab PB Blaster on the bolts being very careful not to drip ANY on or near the transmission output shaft seal.