Is there a visible way o practical way to know yo have LSD??

[jondee86]

The clutches are loaded up by the wedging action of the specially
shaped spider gear shaft as it drives forward. The angled faces try to
push the thrust blocks apart, and this applies pressure to the clutch packs.

Bill Sherwood has a diagram on his excellent site, that shows (simplified)
the differences between 1, 1.5 and 2 way LSD units. You can see it here :

http://www.billzilla.org/lsdoptions.jpg

The "wedging" action only happens when the diff is transmitting torque
to the wheels. When coasting or lightly loaded, the diff behaves pretty
much like a standard "open" diff. Unless of course, you have shimmed
the clutches up to have a high preload. Then, even quite a small torque
load will lock the clutches up, and the diff will act like it was welded !!!

Cheers... jondee86