Gear oil is different from the engine oil. It is thicker than other automotive fluids and used to keep the gearbox lubricated. Since maximum automotive components are made of metal, so if they don’t stay lubricated, then they can cause a reduction in the vehicle’s overall performance. Like other fluids, gear oil also gets contaminated with time. Noisy transmission is the most common sign of failing differential oil. Jerking transmission, burning smell- are some other typical symptoms associated with bad gear oil. If your vehicle’s gear oil is found dirty, then replace it by appointing a skilled car professional so that you can prevent the gearbox from getting damaged severely.