How Many Times Should the Transmission Fluid Be Changed by Gravity?
2 Answers
Changing the transmission fluid by gravity requires 2-3 times to thoroughly remove the sediment. If possible, it is recommended to change it three times for a cleaner result. Additional Information: 1. If transmission fluid is used for too long, sludge will settle at the bottom of the transmission oil pan, causing the fluid to become dark and thick. This affects the lubrication performance of the transmission, leading to car jerking and rough gear shifting. Although a transmission fluid exchange machine can be used, these deposits are difficult to remove through the cooling lines, and the cost is higher. 2. Gravity transmission fluid change method: Unscrew the drain plug at the bottom of the car's transmission, allowing the fluid to flow out by gravity. The fluid will appear much clearer and more fluid compared to the previous two changes. Once the fluid stops draining, tighten the plug and refill with new fluid. It is generally recommended to perform the change at intervals of about 300 kilometers.
As a mechanic who frequently handles car maintenance, I tell everyone that gravity-based transmission fluid changes shouldn't be done just once. The gravity method relies on the fluid flowing out under its own weight, but transmissions are complex - areas like oil passage corners always retain significant old fluid residue, meaning a single change only replaces about half the fluid, leaving new fluid easily contaminated. I typically recommend owners perform two or three changes: first draining most old fluid, then driving for several days to allow new fluid to mix with remnants, followed by a second change after a week. This removes about 90% of contaminants, significantly extending transmission life. Don't cut corners with a single change - neglecting this often leads to gearshift hesitation or even overheating failure. Performing dual gravity changes every 40,000 km is a wise choice to ensure smooth driving.
