#GearOil

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 sending it to two rear tires. The whole time, it is letting those two rear tires spin at different speeds. In the case of a limited-slip differential, it’s also making sure power goes to both rear tires. It’s tough work and it’s dirty work and it is why that quart or two of fluid in your rear differential is so important to long life. Here are 5 of the best differential fluids on the market, how to change it, and when to change that rear differential fluid.