Anything really, grease oil wd40 anti seize, a fresh coat of paint, just be sure to take it out every once in a while and rust will not be able to intertwine and tighten up and essentially weld itself tight
Try out what I just suggested, having constant tension while tapping can do more good than pizz pounding it head on even.
I had one stuck in my Tahoe like that, soaked it down over three days with PB Blaster, still had to beat the living crap out of it to get it out after I heated it up and cooled it off quick with water a couple of times to break the rust loose , after that I took it out after every time I got done using it, didn't want to go through that bullchit again . The Curt hitch on my jeep doesn't fit that tight for some reason so I never worry about it. I would imagine that gray anti seize that you use on brakes and such would work or grease
Take it out and throw it in the tool box when done towing, you wont hit your shins on it that way,......... and Oh yea, Vaseline, it washes off easier if you get it on anything...........
People always give me a weird look when they see the gigantic tub of Vaseline sitting with my other lubricants in the garage. It is pretty awesome stuff to have around the shop.
Yup, big tub of Vaseline and rubber medical gloves are on a shelf Sometimes need to perform surgery !
This coming from a guy that dives with Sharks on purpose! I use a lot of never sieze always put gloves on as that stuff is impossible to get out from underneath your finger nails! My Dad sold family home and went to a retirement community so he stores all his stuff at my house (garage / Barn) He's 70 so part of the generation of fix it don't throw it out and buy a new one... He's dad so we do it his way even if it don't make sense... The 1986 cub cadet is his if I can get bolt out without a torch and tap and die set it a good day.. 2 months ago he paid 700 dollars to put new motor on his wood splitter without talking to me.. Dad a 100 bucks more I would have gotten a new one... which reminds me got to get oil filter off that before work..
I had one stuck really good in a 2000 Dodge Durango, soaked that thing with pb blaster and wailed on it with a 12 lb. sledge for a whole day. Next day I chained it to a tree, four low and go. Came to a halt at the end of the chain I ended up selling that truck with it the hitch still stuck in there
Soak it with penetrator from both sides...every day...for a couple days. Get out the BFH and go to work on it. If it won't wiggle with the BFH then no amount of pulling on it will work. If that doesn't work....time to get out the hot wrench.
Any reason you can't try spray graphite or silicone to loosen it up? I don't know, I don't have a hitch - really just asking for curiosity's sake.
This happened to me once. I tried all kinds of lube and even beat on it with a 20lb monster maul. I gave up on that. I backed the truck into a huge rock going about 3mph. Then I chained the insert to the rock and drove forward putting constant tension on it. It popped loose. I really think the backing it into the rock did most of the work.
Zap, that may very well be a law in most states but I do not think it is ever enforced. But just to be safe, I'd always take it out when not being used. Who knows? It might save a lawsuit if someone broke a kneecap or hit you from behind or you backed in to someone. Better safe than sorry and then no problem getting the danged thing out either.