Two main types of LSD have been generally used - mechanical (geared or clutch-based) and fluid based (viscous).
LSD Limited Slip Differential
VLSD- Viscous Limited Slip Differential
Nameless EJ6 wrote:I *think* I know exactly what they are!
Ya see, your regular LSD utilizes clutch packs. With your VLSD, there is no clutch packs, it's just a gob of gears! I think they call it helical?
Wait.. there's something seriously wrong with what I said.
Viscous The viscous type is generally simpler, and relies on the properties of a dilatant fluid - that is, one which thickens when subject to shear. Silicone-based oils are often used. Here, a chamber of fluid rotates with the normal motion of the output shafts, but a differential motion causes paddles or vanes to move through the fluid. The greater the speed of the vanes, the more resistance the fluid will put up to oppose this motion. In contrast to the mechanical type, the limiting action is much softer and more proportional to the slip, so for the average driver is generally much easier to cope with.
Viscous LSDs are less efficient than mechanical types, that is, they "lose" some power. However, they are less prone to breakdown as long as the fluid is changed regularly.
HLSD- Helical Limited Slip
Helical refers to the kind of gears used. they are cut with helical teeth and as they receive more and more spinning torque they start to push away from each other and they push the plates together causing the locking effect
For road racing, many prefer a helical limited slip differential, because it does not lock the two output shafts to spin at the same rate, but rather biases torque to the wheel with more grip by up to 80%.
Clutch limited slip differentials use a center cam that moves within a casing as the torque changes. The casing is made up of two symmetrical left and right segments. However, the cuts in the casing making the notches for the cam to slide in are not. That determines 1, 1.5, or 2-way LSD. As the cam slides in the notch, it pushes the casing outward, engaging a series of clutch discs--some attached to the casing, some to the output shafts. When engaged, both output shafts will rotate at the speed of the casing, making both axles and subsequently both wheels, rotate at the same speed.