Is Transfer Case Oil the Same as Transmission Oil?
2 Answers
Transfer case oil and transmission oil are not the same. Transfer case oil is differential gear oil and does not have a fixed replacement cycle. On the other hand, transmission oil is designed to keep the transmission system clean and maintain its normal working condition, while also extending the lifespan of the vehicle's transmission components. Generally, the transmission oil for automatic vehicles should be replaced every 3 to 4 years. Below are the detailed explanations: 1. Manual transmission oil is typically replaced every 2-4 years or 60,000 kilometers, depending on factors such as the driver's proficiency in operating the vehicle, the road conditions the vehicle frequently encounters, the mileage driven over a certain period, and whether high-speed driving is common. 2. These factors determine the actual replacement cycle and mileage for gear oil. As long as gear shifting remains smooth and there is no significant change in transmission noise, there is no need to worry too much. However, it is advisable to regularly maintain the vehicle at a 4S shop. 3. Generally, the replacement cycle for transmission oil is calculated in the same way as the vehicle's maintenance cycle, primarily based on mileage or usage time. If the vehicle's manual specifies these two indicators, the earlier one must be followed. 4. If the vehicle manual does not provide such indicators or does not clearly state the oil change interval, manual transmission oil can usually be replaced every 20,000 to 40,000 kilometers.
I've noticed many people wonder whether transfer case fluid and transmission fluid are the same, but in fact, they are quite different. The transfer case is used in four-wheel-drive systems, such as for power distribution in SUVs, and its fluid focuses more on pressure resistance and high-temperature protection, typically being a high-viscosity gear oil like SAE 75W-140. Transmission fluid, on the other hand, is categorized as ATF or MTF, primarily lubricating the gear-shifting mechanism with lower viscosity and emphasizing smoothness. The additive formulations differ significantly, and mixing them can lead to component wear or even failure. When maintaining my vehicle, I insist on changing them separately, as the manual clearly specifies the brand and intervals, recommending checks every 30,000–40,000 kilometers to ensure safety. Skimping on this during daily driving might save a little money but could result in major repairs—it's better to stick with regular professional maintenance.
