Care for your transmission; change the fluid regularlyIf the engine is the heart of your car, then the transmission is its nervous system. It's the core part responsible for delivering power to the wheels and keeping everything else in sync. For high-mileage cars, disregarding proper transmission maintenance is like asking for trouble and hoping it doesn't respond. While transmission fluid helps lubricate, cool, and clean the internal parts of your car, heat and friction can cause it to slowly degrade over time. As a result, shifting could become difficult, parts could wear out faster, and your transmission could overheat or malfunction completely.It is necessary to change your transmission fluid on a regular basis, but you should also follow your car manufacturer's recommendations. While some suggest flushing every 30,000 miles, others propose flushing every 60,000 miles. In any case, leaving it on for too long is risky. Burning smells, slipping gears, delayed acceleration, or dark, gritty fluid are often telltale signs that you have waited too long. If your car is automatic, have a professional check the fluid's level and quality periodically.