To perform a differential oil change, loosen the differential drain bolt, remove the existing gear oil and the gear oil fill bolt, add the gear oil and reinstall the fill bolt. A differential oil change is a full flushing and replenishing of the gear oil in the differential system.
The process of the differential oil change distributes engine power to the wheel axles. The first step in the process is to raise the car onto a jack and remove the differential drain bolt. This allows the old oil to leave the system. Once the oil is completely gone, replace and tighten the drain bolt to prevent the new oil from leaking out of the system.
The final phase of the process involves replacing the fluid, which means finding the differential fill bolt and removing it. Use a pump to transfer the correct type of gear oil from a can into the differential system. Don't fill the system too quickly, as this causes air bubbles to enter the system and eventually cause issues once the fluid begins to circulate. Once the differential oil starts to overflow, stop pumping the oil and replace the differential fill bolt. Check the drain bolt to make sure that no oil is leaking from the system.