What is a Differential in Cars and How Do They Work? – Mr Parts ©
(Before you place your order please contact us to confirm price. We wish to serve you better!)

What is a Differential in Cars and How Do They Work?

Posted by Auto Surgeons on

An automotive expert may tell a customer, "We need to change the differential oil," and the customer may have no clue what he's referring to.  So many times we'll hear words related to our cars and not even understand what they are.

So What is a Differential? 

A differential is found on all modern cars and trucks. It is part of the front and/or rear axle assembly.  The axle is the central shaft that the wheels on the vehicle rotate around.  The photo below shows where it's located on a vehicle with a four wheel drive automatic transmission.

Car Differential


How Do Differentials Work?

The differential allows wheels on the same axle to rotate at different speeds. When your vehicle goes around a corner the wheel on the outside has to travel faster than the wheel on the inside. The differential allows this to happen. Two wheel drive vehicles have one axle and four wheel drive vehicles have two. Also note that the front wheels travel a different distance than the rear wheels.

For the non-driven wheels on your car -- the front wheels on a rear-wheel drive car, the back wheels on a front-wheel drive car -- this is not an issue. There is no connection between them, so they spin independently. But the driven wheels are linked together so that a single engine and transmission can turn both wheels. If your car did not have a differential, the wheels would have to be locked together, forced to spin at the same speed. This would make turning difficult and hard on your car: For the car to be able to turn, one tire would have to slip

Differential in Front Wheel Drive Cars   Differential in Rear Wheel Drive Cars


Why do I Need to Change the Differential Fluid in my Car?

On front wheel drive vehicles the axle/differential assembly is located in the transmission axle assembly (transaxle). The differential fluid or oil in transaxles and axles should be changed as part of a preventive maintenance schedule. It’s part of your transmission service. Some four wheel drive vehicles require changing the axle oil every 30k miles. On other vehicles it’s every 60k miles or more. This service can lengthen the lifespan of your differential. Consult your vehicles handbook for your manufacturer’s recommendation. If you use your vehicle in extreme conditions then change it more often. In the photo above, the point of the arrow at the front differential is touching the cover. This protective cover holds the oil in the cavity where the gears are.

The photo below is a 3D rendering of a differential. You can see the gears, and as you can imagine, they need to be kept well lubricated in order to deliver optimal performance.

Car Differential in 3D

So, the next time your automobile service adviser mentions changing the differential oil, you'll know exactly what he's referring to.



Having car problems? Then worry no more. Feel free to contact us anytime and our team of experts and mechanics will attend to your needs.

Come back to Mr Parts blog next week for more news, consumer advice, opinions and details on the best car parts for your make and model. Visit us at www.mrparts.ng for advice or to see our product range with your own eyes

(Credit to:  www.baautocare.com - Brian England,              auto.howstuffworks.com - KARIM NICE)

Share this post

← Older Post Newer Post →

Leave a comment