Matt55

I think this info could be beneficial.

A differential is a device that changes the direction of engine torque and allows the drive wheels to rotate at different speeds.

The differential allows each of the drive wheels to rotate at different speeds by splitting engine torque when the car is turning a corner the side and pinion mate gears cause one axle to receive more torque and subtract it from the opposing axle. In automotive applications, the differential housing is sometimes called a "pumpkin" as the differential housing typically resembles a pumpkin also known as "Chunks" also the entire assembly is usually called a "rear end". For Front wheel drive cars their is no separate housing, the differential is located within the transaxle. There are some rear wheel drive cars with transaxles.


The differential uses 2 side gears(which the axles spline into) and 2 spider or pinion gears. A pinion shaft or a pin passes through the 2 pinion gears in the case.

All wheel drive and full wheel drive cars utilize three differentials(front/center/and rear). The center differential in an All wheel drive vehicle allows the front and rear wheels to turn at different speeds themselves, while the front and rear diffs control the individual wheels.



So without a differential the result is the inner wheel spinning and/or the outer wheel dragging, and this results in difficult and unpredictable handling, damage to tires and roads, and strain on (or possible failure of) the entire drivetrain. This is the effect of a welded differential. By physically welding all gears or the 2 pinion gears to the case or carrier.


Axle ratio's

The final gear reduction in the drive train occurs in the differential. The amount of torque a gear set delivers depends on the gear ratio between the drive pinion gear and the driven ring gear. This is referred to as the axle ratio.
To find this ratio, divide the number of teeth of the ring gear by the number of teeth of the pinion gear
so


This is how the problem would be set up: Ring gear(41 teeth)/ Pinion gear( 10 teeth)=4.10(axle ratio)

Example ^.

For higher performance, you can replace a high ratio(low number) rear axle with a low ratio(high number) rear axle.

A higher axle ratio allows the engine to rotate faster. Since most engines provide more toque with higher rpm(up to a certain point), this allows more torque to be applied to the drive wheels. Not only does the engine produce more torque but the higher number gear ratio also multiplies the the available torque by the higher number.

Torque flow:

Open differentials: open diffs supply equal torque to both wheels at all times. The cross shaft applies a drive force to the spider gears. The side gears apply reaction forces that counter this drive force. Because the spider gear can rotate freely the two reaction forces are equal. As the side gear applies force to the spider gear, the spider gear applies an equal and opposite force. It is this force that supplies the torque to the axle that drives the wheel. Because the force on each side gear is equal, the torque supplied to each wheel is equal. This is always true whether one wheel is spinning faster than the other.


LSD-Limited slip differentials:
A car with an open diff spinning a tire the opposite wheel doesnt get enough torque to move the car. To solve this, you have to apply more power to the side gear attached to the spinning axle. By forcing the side gear against the revolving case this bypasses differential action, allowing the case to drive the side gear directly. So by literally pushing the side gear out of mesh with the spider gear against the case.

a lsd applies torque to both wheels evenly or unevenly.

There are several methods use to accomplish this: Preloaded clutches

Cone type

viscous coupling

eaton locker

torsen

Im kind of tired of typing so Im going to leave it at this: Additions, helpful comments are welcome and appreciated