While it’s likely seldom done, some vehicles’ maintenance schedules do include an interval for changing the differential fluid, though perhaps only under “severe service” conditions such as frequent ...

As far as car fluids go, differential oil is one of the most neglected pieces of maintenance. It could be because the effects of not changing differential fluid on time aren't as immediately obvious ...

It starts out as a small oily smudge on the outside of the brake's backing plate. You notice it, but ignore it. Next time you look, there's oil and absorbed dirt making a mess all around the wheel.

Let's be honest, the average person has never thought about whether differentials even have fluid. They're not like engines, which require oil changes after about 5,000 to 10,000 miles (or 12,500 if ...