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How Often Should you Put Transmission Fluid in your Car?

A Car mechanic drain the old automatic transmission fluid.

Are you wondering if you should put transmission fluid in your car? The debate about changing transmission fluid has been raging on for years. But there are mixed opinions.

For instance, some experts say you should change it at 100,000 miles. Others recommend 60,000 miles. So, which is which?

What exacerbates this problem is that some car manufacturers neglect to furnish the right information.  For example, maintenance schedules of some recent cars don’t mention anything about transmission fluid. They leave drivers to guess for themselves. 

In this article, I’ll weigh in and give you my opinion. I’ll explain why crucial to change the transmission fluid. Also, at which miles you should change it.

But before I dive in, let’s clear this right up.

Does changing transmission fluid in your car matter?

The answer to that question is a resounding yes. But you have to know when and how to put it. Knowing exactly when is the right time to change transmission is not easy.

If you ask friends around, you are likely to get mixed opinions. This will leave you more confused, especially if you’re not someone well-versed in the mechanics. 

Common signs that you need to change your transmission fluid:

A car engine with a metal cone transmission oil fill up.

If you are still unsure when to change your car’s transmission fluid, use the dipstick with a clean rag. Be on the lookout for the following signs:

  • Use the transmission dipstick with a clean rag. Check the color of the transmission fluid. But, most new cars don’t have a transmission dipstick. In such a situation, checking your maintenance schedule may help you. 
  • If the color is bright pink, the transmission fluid is still new. 
  • If the fluid looks light brown, you should consider changing it soon.
  • If the transmission fluid is dark brown, you need to change it immediately.

Causes of transmission fluid to wear out

There are a couple of things that make your car’s transmission fluid wear out over time. Let’s take a look at some of them: 

1. Leaks

A liquid leaked out from the engine down to the floor.

The first thing you need to look for is transmission fluid leaks. Such leaks may drip from the seal between your transmission and your engine. At first, it may not be apparent if the leaks you’re seeing are engine oil or transmission.

But once you pay close attention to the fluid, you’ll quickly notice the red color.

2. Transmission gears

Disassembled transmission gears

Faulty transmission may be one of the reasons your transmission fluid leaks. When your gears are no longer working correctly, they will usually block fluid rotation.

3. A clogged transmission fluid filter

In most cases, when your transmission filter is not clean or clogged, the fluid will have problems flowing through properly.

4. A broken torque converter

A broken torque converter may be one of the leading causes of the transmission fluid leaking. When your torque converter is faulty, fluid won’t flow throughout the transmission. In most cases, when this happens, gears won’t work properly.

Using the wrong transmission type

There are various types of transmission fluid. They include automatic transmission fluid, manual transmission fluid, synthetic, or specialty fluids. Using the wrong transmission fluid type may cause your fluid to wear out more quickly than usual.

So it’s always advisable to use the right transmission fluid on your car.

When should you change your transmission fluid?

Expert Car Care recommends changing transmission fluid every 30,000 to 60,000 miles. At the same time, other experts recommend changing transmission fluid every service interval. That may mean it shouldn’t exceed 100,000 miles for a new car. 

The most important thing is that failure to change transmission fluid regularly may affect the bearings and gears! And I guess you’d know what happens next when your gears are not working properly. I advise changing your transmission fluid every 60,000 miles or so

If your car uses lifetime transmission fluid, you may want to check it for around 100,000 miles. While at it, check if the vent tubes are still in good condition. However, if you use your car to tow, transport goods, people, and so on, change your transmission between 25,000 and 60,000 miles.

And if you have a manual transmission, I recommend changing the fluid about every 50,000-90,000 miles. Remember, the making of your car determines when you should change your transmission fluid. For example, if you drive a Ford 150,000 miles.

Most mechanics would disagree with this and suggest changing it every 50,000 miles. 

Final Thoughts

Lastly, changing transmission fluid on a high mileage car can be pretty risky. For instance, a vehicle that has reached 300 000 miles or above. When trying to flush transmission fluid, the varnish and other debris may wash away and cause additional problems.

That’s why I always advise drivers to take to their cars for transmission service. They have mechanics that know when and how to change your transmission fluid.