What Oil Should Be Added to the Transmission?
4 Answers
Transmission oil depends on the type of transmission: manual transmissions require gear oil, while automatic transmissions use transmission fluid. Functions of transmission oil: 1. Alter the transmission ratio to expand the range of torque and speed variation in the driving wheels; 2. Adapt to frequently changing driving conditions, allowing the engine to operate under favorable conditions; 3. Enable the vehicle to reverse while maintaining the engine's rotational direction; 4. Utilize neutral gear to interrupt power transmission, facilitating gear shifting or power output. Proper maintenance methods for automatic transmissions: 1. Check the automatic transmission fluid by testing its viscosity between fingers; replace it if discolored or with a burnt smell; 2. Inspect the manual shift mechanism, adjusting the linkage or cable connecting the shift lever to the manual valve, ensuring the manual handle's position corresponds with the spring clip inside the automatic transmission.
As a veteran driver with 10 years of manual transmission experience, I know transmission oil is no trivial matter. Manual transmissions generally use 75W-90 or 80W-90 gear oil, while automatics require specialized ATF fluid. My old car taught me a lesson - once I used incorrectly viscous oil to save money, and cold gear shifts felt like poking iron blocks. Only after switching to the manufacturer-recommended GL-4 grade oil did it smooth out. Always consult the manual for the most accurate oil change interval - typically every 60,000 km, sooner for frequent off-road driving. Remember: transmissions are more delicate than you think - wrong oil can make shifting mechanisms temperamental in minutes.
Last time I changed the transmission fluid myself, I realized there's a lot to it. First, you have to crouch under the car to locate the drain plug and fill port. If the old fluid comes out black with metal shavings, it indicates severe wear. For manual transmissions, 75W-90 gear oil will do, but for automatics, you must look for the ATF label. I specifically bought a fluid pump for the job, otherwise it's impossible to pour the oil in. The key step after refilling is to check the fluid level—with the engine running, the oil must cover the dipstick marks, top up if insufficient. Don't believe the 'maintenance-free' claims; deteriorated fluid can still make your transmission retire early.
New car owners, pay attention: Transmission oil is not something you can mix randomly! My best friend's automatic car once needed a major repair due to using the wrong oil. Checking the owner's manual is the most reliable method, usually found in the 'Fluid Specifications' chapter. Japanese cars often use ATF TYPE T-IV, while German cars prefer oils with LT71141 certification. Last time during maintenance, the mechanic taught me how to identify oil quality: good oil doesn't smell burnt and appears as a translucent red when rubbed between fingers. For automatic transmissions, it's recommended to go to a professional shop for an oil change—they use a circulation machine for a thorough replacement, whereas gravity draining at home only removes about half of the old oil.
