Originally Posted by wdkwang

The actual locking mechanism of the VLSD is a fluid sealed inside (and can only be accessed when taken apart), which gets hot very quickly and stops working after about 10 minutes of drifting in my experience. At that point, it acts like an open-diff and needs some time to cool off. It is said that changing the fluid out of the pumpkin would not effect the locking efficiency of the VLSD. I found this to be true in my experience, as well, when i changed the OEM fluid around 15k miles to Redline. No difference.
So to sum it up, if changing the diff fluid makes no difference in performance, why are we doing it at all in the first place?