Ok now I understand that it is a full lock up under acceleration and partial lock up in deceleration. But my question is how does it get partial lock up. I can't figure it out. It seems like it would lock, unlock, lock, unlock. Wouldn't that upset the car enven more than help stableize it?

 

Is your friend.
http://www.kaazusa.com/introductionToLSD/i...tion_To_LSD.htm

 

I have already seen this and it still does not expain how it work. My question is how does it manage to achieve half lock up it just doesn't seem possiable I think it is just a marketing thing.

 

It's not actually 'full lock up' or 'half lock up', they're referring to a relative amount of locking within a clutch-style limited slip diff.

In forward acceleration there are a set of wedges that are driven apart, forcing clutch packs to engage and provide friction to reduce one wheel spinning relative to the other. In a 1-way diff, there is no spreading of these wedges at all on deceleration, so there is unlimited slippage between the wheels.

In a 2-way diff, there is exactly as much friction in deceleration as there is under acceleration.

In a 1.5-way diff, there is something in between those two extremes. How much is dependent on the angles of the ramps.

1, 1.5 and 2-way are relatively new terms, ask any old motorsports guy what they mean and they'll give you one of these: They just refer to the relative angles of the ramps within the diff.