Back to all

What Is a Differential and Do You Have One?

October 5, 2016

With front-wheel drive being so common these days in Joliet, Illinois, the differential is just taken care of during a transmission service, so most Joliet drivers don't even have to think about it. And rear-wheel drive differentials don't need to be serviced for years, so it's understandable that it's not something on the top of Joliet customers' minds. It's not uncommon for drivers to not know they have a differential let alone know that it needs service.

Call Tuffy Joliet (South Plainfield) in Joliet at 815-436-1829 for information about differential service, or stop by our Joliet, Illinois, auto center at 2031 SR 59, 60586.

To better understand what a differential does, think about our local Joliet high school track. There are lanes marked off on the track. For the longer distance races, the starting lines are staggered. The starting lines for the outside lanes are ahead of the starting lines for the inside lanes. That's to compensate for the longer length of the outside lanes. Staggering the starting lines means that each runner has the same distance to run.

The differential compensates for the difference in speeds between the inside wheel and the outside wheel in a turn, because they have to travel together through slightly different distances.

It's a very important function. When you think of it, all the power to get a vehicle moving goes through the differential. Most cars in the Joliet, Illinois area weigh between 3,000 and 6,000 pounds (1,400 and 2,800 kg) – trucks even more. The power from the engine goes through the transmission and then through the differential to the drive wheels.

That's a lot of work and requires very heavy duty parts. And those parts need protection. The differential fluid lubricates the gears in the differential and keeps them cool.

The fluid eventually gets dirty and worn down. Some kinds of differentials require special additives that break down over time. So vehicle manufacturers recommend intervals for replacing your differential fluid.

The professionals at Tuffy Joliet (South Plainfield) will drain the used fluid and check it out for metal bits, which could be a sign of excessive wear on the gears. Then they’ll replace the fluid and install the additives if necessary.

Your Tuffy Joliet (South Plainfield) service advisor can look up the vehicle manufacture's recommended service interval or you can check your owner's manual. Give us a call at 815-436-1829 for more information about your differential service.

Tuffy Joliet (South Plainfield)
2031 SR 59
Joliet, Illinois 60586
815-436-1829

More articles from Tuffy Joliet

It's (Not) Complicated (Engine Air Filter)

March 29, 2026

While many components of your vehicle are complex and composed of lots of mechanical and electrical parts, there's one that isn't complicated but still important. It's your engine air filter. (And, we should point out, the engine air filter isn't to be confused with the cabin air filter. The ca... More

The Last Gas (Fuel Pump Replacement).

March 22, 2026

You're heading down the road and you notice your vehicle is sputtering, like it's running out of gas. But the gauge show's it's still got a quarter of a tank. So what gives? It could be that your fuel pump is failing, meaning your engine is not getting enough gas to run properly. While fuel pu... More

Don?t Skip Out on These! (Vehicle Maintenance Items You Should Never Postpone)

March 15, 2026

Maybe that little sticker on your windshield is giving you the reminder that its time for your vehicle to have an oil change. Youve thought, Aw, I can skip this one and save myself a little money. When it comes to things you should never ignore on your vehicle, timely oil changes are number one... More