LSD or not how to tell

Torque, thats what my torque wrench says. When I was buying my truck mechanical LSD was a option that can be added either from factory or at the time of purchase, or.... after the purchase. I dont see why somebody would not be able to to just say ok I want reg cab please install LSD for me before I buy it.
Also I did not say LSD works like locker I am only saying that it does transfer power even with the wheel in the air. How much power is solely depended on in what state LSD is. Its not gonna lift you by one wheel over big rock. But if you are balancing on two wheels it will push you over for sure.

 

If you are having to use brake at all then your LSD is fried, may not be injured to the point of not working but it is not limited slipping anymore. An open diff can be fooled to work kind of like an LSD if you feather your brake properly. JOE>