When a post is first created and you realize you may have placed it in the wrong forum, you can copy the text you have written, and repost it in the correct forum without having to retype. Afterwards, you can then delete the initial incorrect post. Once a post has reponses though, you wouldn't want to delete it though.
Moderators do have the ability to move posts and also "shortcut" them in multiple forums. In this case, I added a shortcut to the Spartan chassis forum for the tag axle question you had posted (I'm assuming that was the thread you were asking about?) The thread will now show up in both forums.
Joe & Shelly, Justin, Tyler, Alyssa | Butler PA
2008 Tiffin Allegro Bus 43QRP|Cummins 425|Honda CRV