Sort of. The 4x4 in general on the early explorers aren't built for major 4x4 action. If I'm guessing he was talking about the hubs. The hubs on the explorer were not the best ford ever made. The seals tend to break causing major problems. On top of that they weren't all that strong and easly slipped out of 4wheeldrive. When you put it in reverse they almost always go into 2wheeldrive. That's one of the reasons most of us here turned to manual hubs. They're stronger and stay in 4x4. Try a search on the site for more info. If you aren't doing any major wheeling though you might not need them.
I would also like to welcome you to the site. You will find just about anything you need right here.