Skip the auto shop - Our mechanics make house calls

How Does a Transmission Filter Work?

transmisison filter

The transmission plays a hugely important role in how your vehicle functions. It's connected to the rear portion of your engine and transfers power from the engine to the wheels. Without a transmission, a vehicle simply cannot move. The transmission filter is a vital part of that system and is situated above the transmission pan, which catches any excess fluid, and below a pickup tube that connects to the oil pump, which regulates the pressure of fluid in the transmission. The transmission filter functions as a sieve to collect contaminants like dirt and debris before sending lubricating fluid to the transmission itself.

How often to change a transmission filter

Over time, bits of metal that have flaked off from metal-to-metal contact and other grit and grime can dirty a transmission filter. Although every vehicle has its own optimal maintenance needs that can usually be located in the owner’s manual, the general consensus among mechanics is that the transmission filter and fluid should be replaced every 25,000 miles. Changing the fluid and filter is a quite messy and time-consuming job because few transmissions are equipped with a drain plug. That means the only way to reach the transmission filter and allow old fluid to escape is by removing the transmission pan. This is often in an awkward-to-reach area and requires special tools, which is why you may opt to consult one of our mechanics about the proper times to change out the transmission filter and fluid for your vehicle and enlist him or her to do the job for you if needed.

Usually, when it’s time to replace the fluid and filter for a transmission, owners purchase an entire fluid filter kit instead of just the filter itself. The actual transmission filter parts are few, but the kits include a little extra related hardware that it’s wise to go ahead and replace as a preventative measure while the transmission pan is already off and that region of the transmission system is easily accessible. These are the items that are generally included in a transmission filter kit:

  • Transmission Filter: The filter resembles a metal plate with slats, which is where the transmission fluid passes through. Inside those slats is a fibrous medium, which catches any contaminants before the fluid reaches the transmission.

  • Gasket: The gasket ensures a tight fit between the transmission filter assembly and transmission pan, so no fluid escapes while it is in circulation. It is held in place by an array of bolts around the perimeter of the pan or may be designed to simply pull off with a little effort. These gaskets can either be made of cork or ridged rubber.

  • Pickup Tube: The pickup tube, which connects the transmission filter assembly to the oil pump is also included as part of the kit.

  • Seal: The last part of a transmission filter kit is an O-ring style rubber seal that ensures a tight fit between the pickup tube and the transmission case.

How a transmission filter works is a relatively straightforward process with few parts involved. If, however, there is any confusion regarding how the transmission filter functions or you suspect it is time to replace your filter or fluid, don’t hesitate to contact one of our highly qualified technicians for a consultation.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Skip the repair shop, our top-rated mechanics come to you.

At your home or office

Choose from 600+ repair, maintenance & diagnostic services. Our top-rated mechanics bring all parts & tools to your location.

Fair & transparent pricing

See labor & parts costs upfront, so you can book with confidence.

12-month, 12,000-mile warranty

Our services are backed by a 12-month, 12,000-mile warranty for your peace of mind.

Get A Quote

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Need Help With Your Car?

Our certified mobile mechanics make house calls in over 2,000 U.S. cities. Fast, free online quotes for your car repair.


Post a question and get free advice from our certified mechanics.


More related articles

How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...
P0121 OBD-II Trouble Code: TPS "A" Circuit Range Performance Problem
P0121 code definition Throttle Pedal Position Sensor/Switch (TPS) A Circuit Range Performance Problem What the P0121 code means P0121 is a generic OBD-II code which indicates that the Engine Control...
P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the P0052 code means This code is seen when the Engine Control Module (ECM) tries to control the...

Related questions

Q: What should I know about the cabin air filter?

Your engine has an air filter, and it serves to protect the engine of the car from damaging dust, pollen and debris. Your car’s Air Conditioning system also has a filter – called a cabin filter. It serves the same...

Q: How Long Does a Transmission Filter Last?

Most transmission filters are designed to filter the transmission fluid of metal particles from normal wear of a transmission. The filter is made from a paper filter media or a fine metal mesh screen. Some filters are an external screw-on...

Q: Check engine light on and car bogging down

Hi there. If the Check Engine Light came on, then there is a problem that the computer is seeing. If the light is flashing, then it may have a misfire. If not, then it is something else in the powertrain....