Had a few trips in my 4x4 (LN106 hilux) which as roughly 333000km's on the clock, and have a rear LSD that seems to be working......

My compliance plate says its a g285 which i understand is a 4.3 ratio with a 4 pinion LSD.
In a few instances now the rear LSD has worked flawlessly, which speaking to others is strange as they tend to not work very well after about 20,000km from factory.
I thought i would send the previous owner a message and ask him, and he never had any issues with it either, or the owner before him. Apparently its just worked!
To put it into context, last 4x4 trip over rocks the rear end was screwing when cornering like a spool would on bitumen, and also when pulling people out / pulling a large tree (both on dirt) both the back wheels have locked up and started spinning. I know these factory units will only transfer some force, and once that force is exceeded they spin freely, but how can you check that? is there a torque method of determining at what force the LSD "breaks" and would that let me know what kind of LSD it might be?
And is there a check for certain types of LSD's that would tell me if its a factory toyo or something aftermarket?
Any input / guidance most appreciated

Cheers, Cuzza