How Often Should I Change Front or Rear Differential Fluid? John Baker | Apr 16, 2019 12:05 PM How often you should change front and rear differential fluid depends on your vehicle, driving conditions and differential fluid quality. That’s a vague answer, but it’s true. If you drive your truck primarily on the highway in temperate conditions and rarely tow or haul , you likely don’t need to change front or rear differential fluid very often. But, if you tow a trailer or haul supplies frequently and the temperature fluctuates as wildly as your health insurance premium , then you need to change differential fluid more often. The only way to know the exact mileage interval is to check your owner’s manual or visit the dealership. Differential fluid change intervals Why the varying fluid-change intervals? Because severe operating conditions break down differential fluid more quickly and place greater stress on the gears and bearings, inviting wear. The truck ma