Limited slip additive, hows it work?
 

what I mean is if I fill up my diff with fluid, and NO additive, will the limited slip work too good and thats why you feel it scrubbing around corners? or does the additive make the clutches stickier enabling it to work better?

With no additive, it will work too good (if there is such a thing!) and scrub the tires, or chatter. The chatter is from trying to hold, then slipping a little then holding, then slipping a little. This is how I run - with no additive. I installed a lsd to hold, not slip.

The other option is to dump in the modifier to help the clutches slip easier, which seems like a oxymoron to me. Why have a lsd the add something to help it slip. The additive is used to help with the chatter and keep people from thinking something is wrong with their truck.

In very simple terms:
On the molecular level anti-slip additive looks like a tadpole. The head "burrows" into the clutch with the tail sticking out. The clutch slips on the tail until until the force from a spinning tire tightens up the clutch pressure causing the lube to be ripped out by it's tail. Lack of lube causes the clutch to grip tighter. When the clutch force returns to normal the heads burrow in again. Visualizing this you can see how too much or little additive causes problems.

Don't ever assume or let anyone tell you how much anti-slip to use, it's individual to each truck. It varies with the type of gear oil you use and the amount of clutch wear. Some oils have anti-slip already added, I don't like them because they can contain too much = LSD doesn't work.

What I do is after changing differential fluid is do some figure 8s in an empty parking lot. If the rear end makes noise in the turns add half a bottle of additive at a time till the noise stops.

cool thanks for explaining it!