Open Rear vs. Limited Slip Differentials

Have you ever wondered how a limited slip rear differential is different from an open rear one? If so, this video has the answers you need:

In the video, Drew shows us the main differences between both types of differentials.

What Is An Open Rear Differential?

An open rear differential allows one wheel on an axle to rotate while the the other can be completely stopped. This is because there is nothing to slow down one wheel that may be spinning much faster than the other.

This is detrimental when traction is limited. For example, a car with one rear wheel on an icy surface and the other on dry pavement will send all the power to the wheel on the icy surface, causing it to spin. The wheel that has traction won’t get any power. As a result, the car won’t accelerate very well.

Many years ago, all differentials were open. The limited slip differential was developed to address the big shortcoming of an open differential.

What Is A Limited Slip Rear Differential?

A limited slip rear differential has a clutch mechanism to keep the wheels from moving at very different speeds. The limited slip rear will transfer a portion of torque to the tire with the most amount of traction. This limits the amount that the tire with less traction can slip, thus the name. This greatly improves traction on slippery surfaces.

Limited slip rear differentials are also called positraction differentials.

Limited Slip Rear Differentials Offers An Advantage Over Open Rear Differentials

Both types of differentials work well on dry roads. Limited slip rear differentials are designed to prevent your tires from slipping where there is less traction. This can happen due to:

  • Road hazards such as ice, sand, oil, or snow
  • Surfaces that offer less traction, such as gravel roads or off road trails.
  • Large objects such as potholes
  • Aggressive driving

With a differential that prevents tire slippage, you’ll enjoy better traction and more predictable driving.

The Physical Differences Between Both Types Of Differentials

If you open up the differential cover on each type of axle, you’ll see several differences.

The gears within both types of differentials look similar, but the limited slip rear has a more complicated setup. A limited slip rear differential has a clutch pack, while an open rear doesn’t. A clutch pack transfers the torque to each wheel.

A clutch pack is often made up of a series of plates with grooves cut out in them. These plates are usually made from steel, aluminum, or synthetic materials. The plates are stacked on top of each other, and connected to each axle shaft. When the axle shafts are spinning at the same speed, the clutch pack is inactive. When one axle shaft starts spinning faster than the other, the clutch pack allows some difference in rotational speed, but still sends power to both.

We’ve briefly described a limited slip differential that uses a clutch pack design. There are several other methods used to achieve the same goal of improving traction. The clutch pack is commonly found in live axle limited slip differentials.

We Carry Both Open Rear Differentials And Limited Slip Rear Differentials

Are you in need of a replacement differential? If so, consider ordering one from Powertrain Products. We remanufacture differentials with high quality components and processes.

Not only do we provide you with the right differential for your vehicle, but we also provide a warranty on our products. We carry both open rear differentials and limited slip rear differentials. If you order a limited slip rear differential from us, we’ll include the fluid. It’s a friction modifier used on all of our limited slip diffs.

We also offer a wide selection of remanufactured transmissions, engines, transfer cases, and more. Check out our catalog of differentials to see if we have any in stock for your vehicle!

To learn more about each type of differential or to speak with one of our professionals, contact us at (843) 663-9000 or fill out our contact form here.