posible its a "gov lock" i dont know much about them chevy LSD's but i would be interested in seeing it,
has anything changed?? did he get bad stuck?? pulled a real heavy load??
slid sideways and hit a curb??
I'm with you on the first one. I don't think he's done much (if any) wheeling, he's pulled my dad's ski boat a few times, I'm not sure about the 3rd. He's 19, and drives like it, so the third option is possible.