To ensure smooth and reliable transmission operation, it’s important to monitor its condition and change the oil on time. This is especially crucial for used cars, as fresh oil helps prevent overheating, oxidation, and corrosion inside the gearbox.
How often to change transmission oil
Every manufacturer provides its own service schedule, but additional factors also affect replacement frequency:
- Driving conditions: dusty roads, off-road use, and heavy loads contaminate the oil faster.
- Driving style: frequent acceleration, braking, and active maneuvering speed up fluid degradation.
- Climate: cold weather increases stress on the transmission.
Regularly checking the fluid level and condition helps determine whether it needs replacement.
Manual transmission (MT)
Signs that MT oil needs replacement:
- unusual noise when shifting;
- gears engage with effort;
- visible oil leaks.
Since MT oil plays an important operating role, it should be replaced every 90,000–100,000 km, or sooner under heavy load.
Automatic transmission (AT)
Symptoms indicating that AT fluid needs attention:
- the dashboard warning light turns on;
- the transmission overheats or emits a burning smell;
- bubbles appear in the fluid — complete replacement is required;
- the oil becomes dark or cloudy.
Transmission oil replacement methods
Partial replacement
A safe and simple method: drain part of the old fluid and refill the same amount of fresh oil. Can be done at home.
Full replacement
Requires specialized equipment that flushes the entire system. Suitable only for vehicles with less than 100,000 km, to avoid circulating metal debris through the system.
Gentle replacement
Ideal for older cars: drain several liters, refill fresh fluid, drive 1,000–1,200 km, then repeat.
Standard replacement
If the transmission is in good condition, replace the fluid, clean the pan, and install a new filter.
Regular transmission oil changes prevent premature wear and costly repairs. When in doubt, it’s best to consult a specialist to choose the correct fluid and replacement schedule.
