SO How does the viscous LSD work? AWD ALL the time?

[94'TSI'AWD]

since my 94 TSI has a viscous rear LSD doesn't that mean that only both back wheels will spin at the same time as the fluid in the diff gets heated up or enough force is applied to the diff fluid that it hardens and causes is to be AWD? My car is AWD but for some reason i managed to do a burnout in gravel doing a very very "Light" launch. All that happened was i spun tires and threw gravel everywhere. I thought we were suppose to have maximum traction all the time?

 

[FotownTSI]

My 91 has the same LSD, Apparently while I was curiously searching youtube on Awd launches, There are some clips showing the launch in slow motion and I noticed that not all 4 tires spin at the same time. The tires take turns spinning from the front then the back. So all 4 tires don't spin simultaneously from what I've noticed so far.

 

[Wicked_Sick]

A viscous LSD transfers torque between the front and rear if one or the other starts to slip.
HowStuffWorks "Viscous Coupling"

 

[mrTalonAWD95]

if your front wheels are spinning at 20rpms, and your rear wheels are spinning the same speed, your LSD doesnt lock. if youre on ice ripping the hell out of it, and your tires are going different speeds, your LSD is going to lock when the fluid starts swirling, and start unlocking when the difference drops back down to none/some.

have you ever read a Jeep owners manual? it says when you put it in full time (locked) 4WD, youre not supposed to go over like 40mph or something like that. its because its fully locked and any wheels spinning at a different rate will destroy the transmission/coupling.