What is a Rear Differential?

A differential is an important component that connects to your drive shaft and directs appropriate power to each wheel on a given axle. Depending on the kind of drivetrain your vehicle possesses, you may be dealing with a “front differential” (usually referred to as a transaxle) or a rear differential — but what is a rear differential exactly, and what different kinds of rear differentials are there?

Rear differentials are usually found on rear-wheel-drive vehicles that are common in commercial fleets and on Milwaukee and Waukesha-area job sites. We’ve covered them in depth below!

How Does a Rear Differential Work?

So, what does a rear differential do, anyway? The answer depends, in part, on the kind of differential that came equipped in your vehicle. We’ve covered the three main types below.

• With the more common “open” differential, a reduction in speed to your inside wheel (for example, while going around a curve), automatically translates to an equivalent increase in speed to your outside wheel. At the same time, both wheels receive equal amounts of torque. Most transaxles perform the same role.
• A locking rear differential, once engaged, does not allow both wheels to spin freely. By ensuring that both wheels spin at the same rate, and applying unequal torque to each tire on the axle, the risk of losing traction or spinning out decreases dramatically. This works especially well in low-traction environments and off-road situations.
• A limited-slip rear differential is a “best-of-both-worlds” solution. This component allows some slip to occur in order to promote tire longevity, but limits the amount of slip in order to improve traction.

If you feel that your differential isn’t doing its job, learn more about these crucial components and find out when you might be due for a differential rebuild.

What is a Locking Rear Differential Good For?

From the above breakdown, it might appear that vehicles with limited-slip differentials are always the right choice for drivers or fleet owners who want to maximize performance and tire value at the same time. While this is often true, there are some cases where a locking differential is preferable.

So, what is a locking rear differential good for? Here, we’ve highlighted a few situations where it shines:

• On Snowy, Wet, or Icy Roads: Locking differentials are preferred where one expects to encounter a variance in traction between wheels. If you’re on the road, they’re mostly useful when the Chicago or Madison weather is working against you.
• On Uneven Ground, or Off-Road: Locking differentials can be useful on the job site, where they make it easier to get moving on uneven ground, especially when carrying a heavy load. In off-road-focused vehicles, a locking differential is certainly preferred.
• On the Racetrack: Most commercial drivers don’t use their vehicles for drag racing or track tests, but those with locking differentials tend to accelerate faster than models with open differentials, at least on straightaways.

Keep in mind that there are both manual and automatic locking differentials. Manual locking differentials can be activated at-will, while automatic locking differentials turn on whenever sufficient power is sent to the wheels.

Find Out How a Rear Differential Works with Our Team!

Interested in getting a more in-depth answer to the question, “How does a rear differential work?” There’s no way around the fact that hands-on experience is the best teacher. Explore our stock of commercial vehicles today, check out more of our guides to heavy trucking, and contact us to see any model in our inventory for yourself.