
When changing transmission fluid, it is essential to replace the filter. Failure to do so may allow contaminants to directly enter the transmission. Transmission fluid is a lubricant that maintains the cleanliness of the gear system, primarily ensuring proper transmission operation and extending the lifespan of the transmission components. Depending on transmission design, it is categorized into manual transmission and automatic transmission. The steps for changing transmission fluid are as follows: 1. Start the engine to warm up the transmission to operating temperature; 2. Remove the drain bolt; 3. After draining the old fluid, reinstall the bolt; 4. Add new ATF fluid; 5. Shift through gears from P to N, D, L1, L2, etc., pausing for at least 5 seconds in each gear; 6. Check if the automatic transmission fluid level is normal.

When changing transmission fluid, it's best to replace the filter screen as well. From handling various vehicle malfunctions, I've seen many lessons. The filter screen acts like a sieve to intercept metal shavings and debris in the oil passage. If used for too long, it can become clogged or damaged, making the new fluid dirty as soon as it's poured in. Over time, this can cause the transmission to overheat or even damage the gears. Especially in vehicles frequently driven in stop-and-go city traffic or on mountainous roads, the filter screen accumulates impurities faster. Although some car owners think they can save money by reusing the filter screen if it still works, the screen itself is inexpensive and easy to replace. Compared to the thousands of dollars for a major transmission overhaul, this small expense is worth it. I recommend checking the filter screen every time you change the fluid. If the fluid is black or the vehicle has over 100,000 kilometers, then it's even more essential to replace it. This will keep your transmission durable and worry-free.

As a car owner, I understand the budget considerations when it comes to changing transmission fluid and the filter. The filter doesn't necessarily need to be replaced every time, but it depends on the actual condition. If your car doesn't run much and the fluid is relatively clean with a fairly new filter, you might save those few dozen dollars on the filter. The issue is that if the filter is aged or clogged, the new fluid can get contaminated and degrade faster, potentially causing transmission problems like rough shifting, which would cost more to repair. My experience is to refer to the car manual, which usually specifies replacing the filter every 60,000 to 80,000 kilometers, or doing it when changing the fluid. Nowadays, most repair shops default to replacing both to avoid disputes. Overall, skipping the filter replacement carries significant risks, especially for older cars. I'd rather spend a bit more to ensure peace of mind while driving.

The stability of the transmission during driving is crucial for safety, and I pay special attention to this detail. When changing the oil, the filter screen must be considered because it filters out impurities, preventing oil passage blockage and insufficient pressure. Neglecting it may lead to shifting failure or hesitation, which is dangerous on highways. Although the manual sometimes suggests that the filter screen can be replaced separately on a different cycle, in reality, the filter screen is often already clogged with dirt when changing the oil. Not replacing it can contaminate the new oil. My practice is to have the technician check the condition of the filter screen during every maintenance service. If the oil is dirty or the filter screen is discolored, it should be replaced immediately. Don’t cut corners—small issues can escalate into accidents, which are far more troublesome. Family vehicles, in particular, require complete and thorough maintenance.

When changing transmission fluid, I insist on following the manufacturer's guidelines, and the filter usually needs to be replaced as well. Requirements vary by vehicle model. For example, German cars explicitly state that fluid changes must be paired with a new filter, otherwise contaminants may remain and affect system performance. The filter is designed to match specific fluid flow, and old ones may have poor sealing or become ineffective. Consulting your vehicle's owner's manual is crucial, as it details the replacement intervals. Failure to comply may void the warranty or shorten transmission life. I learned this the hard way after ignoring it and experiencing transmission noise—now I perform complete regularly to ensure everything is done properly.

I often perform DIY transmission , and I always replace the filter when changing the oil. The filter is cheap and easy to find, while the old one accumulates dirt and grime. If not replaced, the new oil will get contaminated immediately, leading to increased wear. During DIY, removing the filter isn't difficult, but be careful not to damage the screws and seals—preventing leaks is key. The process takes about half an hour and only costs a few dozen yuan extra. If the filter still looks new, you might delay replacement, but betting on its condition is risky. Transmission repairs are time-consuming and expensive, so replacing everything at once saves effort and extends lifespan—that's why I do it every time.


