Originally posted by Boxxerace
Torque bind will generally result from a worn or locked up center differential. Side to side tire drag can happen with full lockers, but never with a Limited Slip. There is just not enough side-to-side grip by the limited slip to prevent the tires from rotating at different speeds.
To give you an illustration, in the snow driving that I have done, I have found I will get stuck on a snowy hill as the wheel on the right side spins and digs in and the left one just stays there motionless. It is eternally frustrating to someone who own's a vehicle with lockers.
Thats not true. Limited slip differntials are the same viscous unit thats in the center diff of a manual tranny. you can destroy them by having miss matched tires left and right.
There are basically two types of LSD (three including computer operated clutches). The mechanical units use either a clone clutch, a clutch pack, or the extreemly complicated haldex (torsen).
The other type is the viscous unit. The Older style (cone and clutch pack) are always transfering power to both wheels equally no matter the conditions. When the car turns, one wheel spinng faster then the other will overrun the clutches and disconnect one wheel from the power. The mass and traction of the tire is transmitted to the clutch springs. This is wny positraction is great in straight line acceleration, trailer towing, etc, but can be a little dicy in snow and ice. With snow tires they are great, and unstopable with studs.
A viscous coupling is a differential waiting for slip to happen, unlike the mechanical units. When one wheel starts to spin faster then the other, the fluid heats up, expands, and "connects" both axles. Another veriosn of this has the fluid inside a piston, and when it expands it engages the clutches.
You can destroy either LSD with mismatched tires. The advantage to the VC over the mechanical is a better feel in turns (as they age the mechnaical can become grabby), and less drag so better gas mileage, and less weight (less parts cheaper to make). The disadvantage is that a wheel has to start to spin for it to operate.
Torsen is best suited for performance cars. Both wheels need to have traction in order for it to function. If either wheel looses all traction, it wont shift power. A torsen can be designed to multiply the torque sent to the wheel with more traction. Most torsen differntials have a manul differnetial lock because if it looses traction, just the one tire spins.
You can see how a mismatched tire can burn out any LSd (though I am not sure about the torsen yet).
Lockers are a completly differnet animal. They override the function of the differntial and lock both wheels together. One can argue in this mode that its really not a differntial.