Know If It's Time To Change Your Transmission Filter!

The transmission in your vehicle is important for the overall stability and operation of your vehicle. Without the transmission, you would not be able to drive your car from one location to the next. It works in conjunction with the motor and the torque converter to help keep your vehicle running smoothly. As a result, even a detail that seems insignificant like a clogged transmission filter can create a lot of damage if you choose to ignore it.

Even though the transmission filter is just one small component that is housed underneath the hood of a vehicle, it plays a major role in how efficiently your vehicle runs. The primary job of this part is to prevent contaminants from getting into the transmission fluid. With a job of this magnitude, there is no wonder why, over time, dirt and debris accumulate on this filter and keeps it from doing its job. There are some things you can look for to know when it is time to change a transmission filter that is clogged.

What Is A Transmission Filter?

As mentioned, a transmission filter keep debris and dirt away from the transmission fluid. However, this filter also helps to keep these particles away from other areas of the transmission system such as the gears.

The filter is located on top of the transmission pan. The transmission pan is responsible for collecting the extra transmission fluid.

The transmission filter also sits under the pickup tube. This tube is responsible for regulating the fluid pressure inside of the transmission.

Before the fluid reaches the transmission, it first goes through the filter. This process helps to reduce sludge buildup, which can have an adverse effect on the moving parts within the transmission system.

What Occurs During A Transmission Filter Change?

The process to change a clogged transmission filter is a simple process. There are some situations in which only the filter needs to be replaced. Other times, a fluid filter kit is necessary in order for some of the important parts of the transmission filtration system to be replaced. This can easily be done while the transmission is accessible and open.

The transmission filter is one of the most important parts of the fluid filter kit. This filter resembles a metal plate that has slats. In each one of these slats there is a fiber-like material that traps all of the contaminants before the fluid enters the transmission.

There is also a rubber gasket included in the kit that helps to ensure there is a tight seal between the transmission pan and the filter assembly. This way, fluid is not able to escape as it moves through the filter.

The seal is made of rubber and it seals the transmission case to the pickup tube. This seal works to prevent fluid or pressure is not loss within the transmission.

When Should A Transmission Filter Be Changed?

Over a period of time, small amounts of dirt, grit and metal begin to accumulate in the transmission filter. Even though each make and model of vehicle has its own schedule for maintenance that is recommended by the manufacturer, on average, the transmission fluid and the transmission filter should be changed between 30,000 miles and 100,000 miles. As stated, recommendations may vary depending on the age of the car and the make/model of the car.

This is a car maintenance task that can be very dirty and can take a lot of time to complete. This is due to the fact that there are not many transmissions that are built with drain plugs. This means that the person performing the filter change must take the transmission pan out of the vehicle in order to get to the filter. It is only by doing that will the fluid be allowed to drain out of the transmission.

It can also be very difficult to reach these areas with your bare hands. Most transmission technicians rely on special tools to get to these areas of the transmission.

So, with that said, what are some indicators that you can look for to decide whether the transmission filter on your vehicle is clogged and needs to be replaced?

Leaking Fluid

The transmission fluid can begin to leak for one or more reasons:

  • Ill-fitting transmission filter
  • Malfunction with the transmission
  • Cracks in seals and gaskets in the transmission
  • Loose gaskets
  • Misaligned gaskets

You will be able to better observe any possible leaks from the transmission if you leave your vehicle parked in one spot for several hours or for overnight.


Hearing your vehicle make noise can be a sign of several problems. However, rattling or clunking noises can also mean that there is a problem with the transmission filter. If the transmission is shifting into gear hard, that could also signal a transmission problem.

You check the transmission filter, and in doing so, you will also be able to take a closer look at the transmission fluid. If either the fluid or the filter is showing signs of excessive wear and tear or there is a large accumulation of contaminants, your vehicle may need a transmission flush.

During a transmission flush, a transmission technician will check to see if there is a clogged transmission filter and will also inspect the fluid. During this time, the technician will also inspect your car for any other possible issues with the transmission or other systems in the car.

Your Car Will Not Change Gears

This is typically the sign that makes car owners the most concerned, especially if they are having problems moving their car out of a parking space or it is having problems climbing hills and inclines. They understand that the vehicle will only have issues changing gears if there a problem with the transmission.

The gears on a vehicle with a manual transmission may grind instead of smoothly shifting into gear. As a driver, you may even be able to hear and/or feel the change. Although this may be a sign that the clutch is worn out, it may also be a problem with the transmission synchronizers. Typically, these issues can be resolved by just changing out the fluid.

If the vehicle is surging forward when you change from one gear to the next, or you hear the gears grinding for no apparent reason, there may be an issue with the transmission filter. It may be malfunctioning, or it may simply be clogged and dirty.

This is a transmission filter issue that you should address as immediately. Have a transmission technician inspect the entire transmission system, including the filter so the right repairs can be made.

Smoke/Burning Smell

This typically occurs when there is a buildup of dirt, sludge and particles in the transmission filter. The burning smell can be especially intense if the transmission fluid also needs changing. In fact, in some cases, when the transmission filter becomes clogged, the smell can cause smoke to emit from the engine.


The most important job of the transmission filter is make sure contaminants are not able to enter the transmission fluid. When the transmission filter is not able to do this efficiently, the transmission fluid will fail to be efficient because it is contaminated.

When the sludge and dirt are able to enter the transmission fluid, it can begin to burn. This can affect the transmission and lead to costly repairs.

The transmission fluid should be checked on a regular basis for both consistency, color and level. Clean transmission fluid is red in color and is clear. If the transmission fluid in your car is dark, black or has a sludge-like thickness, you should schedule an appointment for a transmission flush.

Noises When Car Is In Neutral

When you car is in neutral, you should not be hearing any noises. As mentioned, any noises coming from your car should make you raise an eyebrow and noises coming from the neutral gear should send out immediate red flags.

When a vehicle is in neutral gear, it should be so quiet that you forget the vehicle is on. The transmission filter and the transmission fluid could be giving you an indication that it is time for them to be changed and replaced. However, if you still hear the noise even after the filter and the fluid has been changed, there may a bigger issue going on with the transmission.

Chances are, if you have read this far, you are likely experiencing at least one of these issues with your vehicle. If you are reaching 100,000 miles on your odometer, and you have not changed the transmission filter, it is likely your vehicle is not performing as well as it could be.

Deciding to DIY to replace a clogged transmission filter is not recommended for a newbie. The majority of your time will be spend draining the old transmission fluid and changing the transmission filter. With some vehicles, the process only involves removing and putting back some bolts and nuts. If your vehicle has a more complex transmission system, the process to replace the filter can be a little more complicated. By taking your vehicle to a trained transmission technician, you will get a professional diagnosis and get your vehicle repaired the right way, the first time.