Differential systems rely on a variety of moving parts, like gears, bearings, and more. They keep your wheels moving properly through every twist, turn, and winding road your vehicle comes across. This process generates a lot of heat while requiring the proper flow of parts moving together. As such, differential systems require fluid to lubricate, cool, and protect these components. Over time, the differential fluid gets dirty, breaks down, and needs to be replaced. So, it is necessary to have your differential serviced regularly. The Easy Honda Service Team recommends having the differential fluid changed every 40,000 to 60,000 miles.