Wd-40 is a joke.PB Blaster and ZEP Penetrating Oil are far superior products.Take that from someone that’s been working on tractor/trailers[and especially cement mixers for 25 years.
I first became aware of PB Blaster in a shipyard in Fairhaven, MA. Mechanics there were using it to loosen up salt water corroded bolts on a propeller shaft. WD-40 has its uses, but when it comes to frozen nuts and bolts, PB is the way to go. jmho