i have manual locking hubs on my 92 ranger.  i think while i was at work, someone locked the driver side one, and not the other.  i know for a fact they were both unlocked when i left it.  does anyone know if having only one can do damage?  on the drive home, i heard a sound, like something was stuck in my tire and kept rubbing the well.  it got worse after about 100 feet, and eventually sounded like metal digging into metal.  i parked it in a parking lot and tried to find the noise, and realized that only one hub was locked.  i'll be the first to admit that i don't know enough to diagnose any kind of axle or locking hub problem.  just wondering if anyone could help at all.  it didn't make the sound while in reverse.

no if both hubs are not locked then the 4x4 system wont bined up witch would make metal noise  

...and you would be driving a 3X3 then.

I had the same problem on an 85 Ford Bronco I was test driving. The passenger side hub wouldn't engage. Sounded, and drove like crap. I took it back to the dealer. I'm not sure what damage this may have caused, if any. I didn't buy that truck, of course, For two reasons: It was a Ford, and it was painted orange. That, and the 3X3 thing.