Is it necessary to replace the filter when changing AT transmission fluid?
3 Answers
Replacing AT transmission fluid does not require changing the filter. The relevant information about transmission fluid is as follows: Transmission fluid replacement interval: Among car maintenance items, transmission fluid replacement is also a very important one. Generally, transmission fluid needs to be replaced every two years or after driving approximately 40,000-60,000 kilometers. However, there is a filter inside the transmission fluid tank, and often when changing the transmission fluid, the transmission fluid filter element is not replaced. Function of transmission fluid: During the use of a car, friction occurs between the mechanical metal components inside the transmission, generating some impurities and metal debris. The function of the transmission fluid filter element is to filter out iron filings, sediment, and other impurities from the transmission fluid, supplying clean transmission fluid to various components, thereby providing lubrication and cleaning effects.
As a seasoned auto mechanic with years of experience, I strongly recommend replacing the filter when changing AT transmission fluid. The filter is a small but crucial component that traps metal shavings, dust, and other contaminants in the fluid, protecting internal transmission parts. Over time, it accumulates significant debris. If you only change the fluid without replacing the filter, the dirt from the old filter can easily contaminate the new fluid. This leads to degraded fluid quality, potentially causing sluggish performance, unusual noises, rough shifting, or even accelerated wear on internal gears. In most cases, the fluid change interval should include filter replacement—typically every 40,000 to 60,000 miles, but always check your vehicle's manual. Spending a little extra ensures peace of mind; the transmission is a critical component, and poor maintenance can be costly. It's best to perform full maintenance every service.
I learned a lesson when driving an automatic transmission car before: I saved some money by not replacing the filter when changing the AT fluid. As a result, within half a year, the transmission started to hesitate, and shifting into reverse always felt sluggish. After taking it in for inspection, the filter was completely clogged, costing me several hundred yuan extra for cleaning and re-changing the fluid. From then on, I understood that fluid and filters must be replaced together. New fluid paired with a new filter ensures a thorough system cleaning. Otherwise, contaminants left inside will dirty the new fluid, making the change pointless. The filter's lifespan is usually similar to the fluid's, so replacing them together isn't costly and avoids frequent rework. The car runs much smoother now—don't underestimate these details.
