I could swear that once upon a time I saw that someone was making a selectable locker that was a truetrac limited-slip when it wasn't fully locked up.
Can't seem to find any info anywhere....
The closest I can find is the Eaton Elocker which is an open differential when it's not locked up.
![Huh??? ???](https://board.marlincrawler.com/Smileys/marlin/huh.gif)