Your vehicle's transmission filter is designed to keep dirt, oil and other contaminants out of your transmission fluid. Over time, as it collects more and more debris, your transmission filter will become clogged and will no longer be able to perform its job correctly, which can have a number of implications on the overall performance of your car. Understanding the warning signs associated with a clogged transmission filter can help you determine when it's time to head to a mechanic to have it replaced before it becomes a serious problem.

Difficulty Shifting

One of the clearest indications that you have an issue with your transmission filter and fluid is if you experience any sort of difficulty shifting up or down. This is because the filter is no longer keeping contaminants out of the fluid, which results in an uneven consistency that can make it much harder for you to change gears, or even for sudden surges of power to occur when shifting. You'll want to get this checked out as soon as possible, as this can greatly increase your risk of experiencing a collision.

Rattling Noises

While rattling can point to a whole host of issues with your vehicle, it can also indicate that there is an issue with your transmission filter—namely, that it is full of debris and shaking loose of its connectors. However, rattling noises alone won't point to an issue with your transmission filter, so look for rattling noises with some of the other symptoms here to determine if your transmission is to blame or not.

Dirty Transmission Fluid

You can also open up the hood and check the color of your transmission fluid to determine if the filter is doing its job properly. Check the transmission fluid dipstick (usually located on top of the engine block, but check your owner's manual for an exact location) to see what color your fluid is: orange and red hues indicate clean fluid, but darker grays, browns or even blacks point to an issue with your filter and contamination within the fluid itself. 

Smoke and Burning

Finally, a severely blocked transmission filter will give off a burning smell as the contaminants are heated to high temperatures. Under certain conditions, this can even cause smoke to start coming out from under the hood. If this is the case, stop driving immediately and head to a mechanic at an auto repair shop straightaway, as you are running the risk of causing severe and expensive damage to your transmission and engine.