Hey loomis. Sorry you're having such a problem. And a messy one too it sounds like!
If it's leaking down at the box, perhaps you don't have the type of box that was expected when you ordered the parts?
Not that we can't make a mistake and send you the wrong part of course, but it's common for these things to have steering gearboxes swapped around over the years. So certainly worth checking.
If that's the case, then yes it could easily be possible for the threaded fitting to be incorrect. Different boxes often have different threads. And even some with the same size threaded hole can use a completely different type of sealed fitting. Some have a standard cone seat for an "inverted flare" to seal against. While others need an o-ring fitting to seal properly.
Can you send some pics in to WH (sales@wildhorses4x4.com) when you call it in? That way whoever is helping you out can see what you're dealing with and even pass the images around for others to look at. Maybe if one can't see exactly what the problem is, another person can.
And post some up here too for sure, so we can all see them. If you don't use an online image hosting site, you can e-mail them to me (or anyone with the yellow "contributor" beneath their username) and we can post them up for you.
Thanks. Good luck.
And again, sorry you're having a bad time with some of our parts. But we'll get to the bottom of it I'm sure.
Paul