Quote:
Originally Posted by FPM III
Good information, but keep in mind, a limited slip is not a locking differential. I'm not knocking you or doubting what you posted. I'm only pointing this out so that folks reading your post and mine above it don't assume that limited slip and locking are interchangeable or synonymous terms. They're two different animals. I've owned both limited slip and locking differential vehicles. I can tell you from experience that they function in a completely different manner. Having had both, I prefer the locking. Some conditions require you to apply the brakes while accelerating with a limited slip- which is not an easy thing to do with a manual transmission.
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I understand the difference between a true "locking differential" and a "limited slip" differential. The practical difference is a locking differential such as an ARB Air locker or electronic locking the differential when locked acts as a spool and both tires must run at the same rotational speed period. This will cause significant binding and wheel scrub in turns. Limited slip differentials work differently in that they have friction plates that tie both wheels together similar to how a locking differential works until the rotational speed is different enough to force the plates to slip. The limited amount of slipping allows turns on dry pavement without significant wheel scrub because the friction plate is slipping not the wheel. That said, there is still pressure on the wheels in this condition due to the requirement that the friction plate resistance be overcome. An interesting side effect of a failing limited slip differential friction plates is that the plates when worn can slip too easily reducing the value of the limited slip differential to nothing. So, limited slip differentials do in fact cause some very limited tire wear as a result of requiring the tire to overcome the friction plates.
Another way to think of this is friction based sway control. In order to turn with friction based sway control the TV must overcome the friction of the sway control which is why you can't use friction based sway control in low traction situations such as compact snow and ice. The theory with friction based sway control is that the abnormal sway caused by passing trucks or wind will be insufficient to overcome the resistance provided by the friction based sway control device. Most limited slip differentials work in a similar manner.
One interesting disadvantage of a limited slip differential is if you are stopped on a hill and have one tire on dry pavement and the other tire on ice if you hit the throttle too hard you can overcome the "limited slip" part of the differential and actually spin the tire on the ice and be unable to move. This however is an edge case and is unlikely to happen except in an "off-road" situation. There is an interesting video on Power Block TV on Spike that shows how a limited slip differential works vs. a spool or locker.