Differential

As the name suggests, the differential is a mechanical device that lets the outside wheel rotate faster than the inside wheel during a turn. The outside wheel has to cover more ground than the inside wheel, and the differential makes this possible.

In a rear-wheel-drive vehicle, the differential is placed prominently between the rear wheels, whereas in a front-wheel-drive vehicle, it’s located in the transmission housing between the universal joints. In an all-wheel-drive vehicle, the front and rear differentials are connected through the transfer case. The differential synchronizes the four wheels on a vehicle.  

The differential is an integral mechanical part that is made up of sturdy gears equipped with ball bearings and immersed in an oil pan. Minimal maintenance is required, but a certified NAPA AUTOPRO technician can check the differential, detect and fix leaks, as well as change the lubricant according to the manufacturer’s recommendations.  

A grinding or scraping noise coming from under the vehicle is the only indication of a problem, so it’s a good idea to get any such noises checked out at your local NAPA AUTOPRO shop.