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Differentials (open differential)
The differential has three main jobs:
1. To direct the engine power to the wheels...
2. To act as the final gear reduction in the vehicle, reducing the rotational movement of the transmission one final time before it hits the wheels
3. To transmit the power to the wheels while allowing them to rotate at different speeds (This is where the differential earned its name.)
The wheels on your vehicle spin at different speeds, especially when turning. As you can see from the diagram, each wheel travels a different distance through any given turn, and the inside wheels travel a shorter distance than the outside wheels. Because of this, the wheels that travel a shorter distance travel at a lower speed. It's also important to remember that the front wheels travel a different distance than the rear wheels.
For the non-powered wheels on your car (the front wheels on a rear-wheel drive car) this is not a problem, as they just spin freely and will turn at different speeds without the need for a differential. However, the driven wheels are linked together so a single transmission can send power to both wheels. If we didn't have differentials, the wheels would be forced to travel at the same speed, making it very difficult to turn...
open differentials always apply the same torque to both wheels, and that is the downfall of this type of differential... Torque will always travel the path of least resistance. So, if one wheel starts to slip, all the torque is transfered to that wheel, leaving the other wheel pretty much powerless. This is where the limited slip differential comes in...
Limited Slip Differentials
Limited slip differentials use various components to allow normal differential action when going around turns. Put in layman's terms, when a wheel slips, they allow more torque to be transferred to the non-slipping wheel.
Manufacturers make LSD's in different configurations and are generally classified as 1 way, 1.5 way, and 2 way. This designation reflects the design of the cam groove which enables the LSD to function differently under different loads. A 1 way differential just means the cam is shaped in such way as to have positive lock (equal torque distribution) only when accelerating. The 2 way differential is constructed in a way to have positive lock motion in either acceleration or deceleration. The 1.5 way differential is a fairly new term used to describe the 2 way cam which allows different lock up rates during the two directional forces. The 1.5 distribute positive lock stronger under acceleration than when decelerating. The 1.5 way can be more forgiving durring braking than a full 2 way setup. However, it is less effective in racing situations. It provides easier operation for beginners (mostly when off the throttle). You see them a lot on front wheel drive cars (FF) which need extra stability during braking...
The differential has three main jobs:
1. To direct the engine power to the wheels...
2. To act as the final gear reduction in the vehicle, reducing the rotational movement of the transmission one final time before it hits the wheels
3. To transmit the power to the wheels while allowing them to rotate at different speeds (This is where the differential earned its name.)
The wheels on your vehicle spin at different speeds, especially when turning. As you can see from the diagram, each wheel travels a different distance through any given turn, and the inside wheels travel a shorter distance than the outside wheels. Because of this, the wheels that travel a shorter distance travel at a lower speed. It's also important to remember that the front wheels travel a different distance than the rear wheels.
For the non-powered wheels on your car (the front wheels on a rear-wheel drive car) this is not a problem, as they just spin freely and will turn at different speeds without the need for a differential. However, the driven wheels are linked together so a single transmission can send power to both wheels. If we didn't have differentials, the wheels would be forced to travel at the same speed, making it very difficult to turn...
open differentials always apply the same torque to both wheels, and that is the downfall of this type of differential... Torque will always travel the path of least resistance. So, if one wheel starts to slip, all the torque is transfered to that wheel, leaving the other wheel pretty much powerless. This is where the limited slip differential comes in...
Limited Slip Differentials
Limited slip differentials use various components to allow normal differential action when going around turns. Put in layman's terms, when a wheel slips, they allow more torque to be transferred to the non-slipping wheel.
Manufacturers make LSD's in different configurations and are generally classified as 1 way, 1.5 way, and 2 way. This designation reflects the design of the cam groove which enables the LSD to function differently under different loads. A 1 way differential just means the cam is shaped in such way as to have positive lock (equal torque distribution) only when accelerating. The 2 way differential is constructed in a way to have positive lock motion in either acceleration or deceleration. The 1.5 way differential is a fairly new term used to describe the 2 way cam which allows different lock up rates during the two directional forces. The 1.5 distribute positive lock stronger under acceleration than when decelerating. The 1.5 way can be more forgiving durring braking than a full 2 way setup. However, it is less effective in racing situations. It provides easier operation for beginners (mostly when off the throttle). You see them a lot on front wheel drive cars (FF) which need extra stability during braking...
