Originally posted by taxxman2k
not sure on all the differences but a locker "locks" the two sides together with teeth and a limeted slip is a clutch pack.
The locker distributes power to both wheels evenly, with no slippage. If you think about an extreme example (spool or "Lincoln Locker) there is no differentation between the wheels ever. This means that the full lockers will not allow one wheel to rotate faster than the other one in a turn.
The ARB locker is only a locker when it is engaged. Other time it acts as an open diff.
A ratchet style locker, such as a Detroit or lunchbox style locker like the No-Slip is 100% locking, but will disengage around turns (coasting), allowing the outside wheel to out accelerate the inside one and disengaging. With the power on, it will engage. Think of these automatic lockers (in simple terms) as having the throttle as an on/off switch.
Because of this, the limited slip is a better choice for streets because it allows differentation, but not so good on the rocks for the same reason. The Torsen is one of the best LSDs you can get and the preloaded one in my FX4 is only about 30% locking.
There are many types of limited slips. Some, like the Ford Track-Lok and Auburn uses clutches which will eventually wear out. However, helical style limited slips, such as the Torsen is all gears and will never wear out (and are considered good for the life of the vehicle). They generally also have more preload or bias and can direct a disproportianate amount of power to the wheel with traction.
This is the oposite of an open diff, which sends power to the wheel that has the least resistance.
--Sean