What are the effects of not changing differential oil?
3 Answers
The effects of not changing differential oil include increased friction between gears in the differential structure, higher vehicle fuel consumption, potential damage to differential and differential lock components over time, and compromised driving quality. Differential oil, also known as gear oil, serves as lubrication for the rear axle gear transmission mechanism. Its primary functions are lubrication and cooling. Due to variations in gear axis positioning and tooth profiles, there are significant differences in contact stress and relative sliding speed at the meshing surfaces, necessitating the use of different gear oils. As a lubricant, differential oil also has corresponding viscosity grades. During high-speed driving, the temperature of the lubricating oil in the differential can become extremely high, far exceeding that of engine oil. In such conditions, the high-temperature viscosity characteristics of differential lubricating oil become particularly crucial.
Last year, I kept procrastinating on changing the differential oil in my car. Eventually, I started hearing a sharp squeaking noise, especially when turning, which made me hesitant to take friends out. When I finally took it to the repair shop, the mechanic told me the oil had turned as black as ink and couldn’t lubricate the gears anymore, causing significant wear and tear on multiple parts. It cost me over 5,000 yuan to fix. Since then, I’ve learned that differential oil needs regular changes—every 20,000 to 30,000 kilometers or once a year. Once the oil deteriorates, it loses its protective properties, increasing gear friction, which can eventually lead to complete lock-up or even require replacing the entire differential. Skipping oil changes not only burns money but also ruins the driving experience. Now, I make it a priority to check this during every maintenance season.
Trying to save money requires wisdom, and I've learned this the hard way. Neglecting to change the differential fluid might seem like saving a couple hundred bucks on maintenance, but the oil oxidizes and thickens over time, failing to lubricate internal components. This leads to rapid gear wear, and repairs can cost thousands. My previous car developed constant strange noises because of this, and when the differential finally seized up, the major repair bill was heartbreaking. In reality, changing the fluid during regular maintenance is a small expense – prevention is the most cost-effective approach. This is especially crucial for rear-wheel-drive vehicles or those frequently driven on mountain roads, where oil degradation is accelerated. Ignoring it not only drains your wallet on repairs but can also cause unstable vehicle steering, posing significant safety risks.
