What are the symptoms that indicate transmission fluid needs to be replaced?
2 Answers
Transmission fluid needs to be replaced when the transmission exhibits some jerking during gear shifts. For manual transmissions, difficulty engaging gears or a rough feel when shifting indicates that the transmission fluid needs replacement. Transmission fluid is crucial for the transmission system. In automatic transmissions, it is used for lubrication, cooling, and power transmission. The control mechanisms of automatic transmissions also rely on transmission fluid to function properly. There are two methods for replacing transmission fluid: the gravity drain method and the flush machine method. The gravity drain method can only remove about 60% to 70% of the old transmission fluid, while the flush machine method can remove 80% to 90%. The flush machine method provides a cleaner replacement, so it is recommended to use this method.
I recently encountered this issue with my old car, and there were quite a few signs when the transmission fluid needed changing. The shifting became very rough, and during acceleration, there would be sudden jerks, as if it was getting stuck, causing noticeable vibrations throughout the car. Sometimes, I could even hear a whining or groaning noise from underneath the transmission, especially when going uphill. Additionally, the fuel consumption inexplicably increased—I remember when the oil pressure was low last time, the fuel consumption surged by a liter or two on the highway. When checking the fluid level, I noticed the color had changed from bright red to dark black or brown, with a burnt smell, and there might even be metal particles mixed in—all signs of degraded lubrication due to aging fluid. If you don’t change the fluid in time, it can easily damage internal gears and valves, leading to costly repairs. I recommend regularly checking the maintenance manual and replacing the fluid every 60,000 kilometers to avoid major issues that could compromise driving safety.
