I realized these sections were being indexed in the sitemap and causing crawl errors because they weren't set to "Private Node", so I went and set them. However now, Guests can view the section and when they click on it they see thread titles. When you click on a thread title it tells them to log in.
I want it, the same as before, where a member clicks on the forum name and is shown no threads, or brought to the login screen. I have the permissions for the node set to Never for everything except "view Node". I have tried turning the private forum off, but it still has the same issue.