If the center diff's spider gears are broken, the car will bind up in tight turns. It's not uncommon to see a DSMer doing figure 8s in the back of the pits after a mean launch to make sure nothing broke
If you cut the case in half (I only know 2 other cases besides me on this one) the car won't move unless you have a welded VC or VC eliminator. Similar situation if the tcase is broken.