Your rear differential is one of the most unappreciated parts in your car or truck. It does what might be the hardest job of all of those components, multiplying torque from your transmission and ...

My BMW i3’s rear differential has been a gigantic pain in the butt in that — thanks to a Technical Cost Reduction by BMW after the first model-year — it no longer features a fill plug. How, then, am I ...

Gear-obsessed editors choose every product we review. We may earn commission if you buy from a link. Why Trust Us? Changing the car differential oil—it's one of the most-overlooked maintenance tasks ...

A differential is one of a car's most important moving parts. It's the thing that takes the torque from the car's driveshaft, and distributes it among the driven wheels. Since there's a lot of ...