Your transmission filter is what prevents dirt and other debris from getting into your transmission. Without it, your transmission fluid becomes a dark sludge, which can cause stalling, gear shifting problems, and a host of other issues. Of course, like any filter, eventually your transmission filter gets clogged with debris. How do you know when it’s clogged, and how do you fix it? Here’s a crash course in fixing a clogged transmission filter.
Signs Your Filter Is Clogged
First, listen for odd noises. You may hear a metal rattling sound, like something loose or jiggling around inside your car. If you drive a stick shift, then the sound may be a whirring noise whenever you shift gears. This could be instead of the rattling, or in addition to it.
If you notice these sounds, check your transmission fluid. Is it bright red, like it’s supposed to be, or has it become brown or black? If it’s the latter, you’ll need to flush your transmission fluid as well as taking care of the filter.
Other signs of a clogged filter include a burning smell, as dirty fluid runs hotter than clean fluid does. There may even be smoke coming from under the hood, which means you should stop the car immediately. Do not pass Go, but go directly to the nearest mechanic.
You also may experience problems shifting gears, or with the clutch slipping. The car may stall at red lights as well. These are common problems when your transmission fluid is dirty, and likewise, common when your filter is clogged. You may notice leaks as well. If, when you take your car out of the driveway or garage, there’s a dark, oily spot on the ground where it was, then your transmission fluid may be leaking. The leak itself will need to be addressed, but it’s also a sign of a clogged transmission filter.
What to Do About a Clogged Filter
Like almost any filter, when your transmission filter is clogged, it will need to be replaced with a clean one. How often this needs to be done depends on the make, model, and year of your vehicle, but it’s usually every 30,000 to 100,000 miles—around the same frequency as your transmission fluid, and your clutch, if you drive a manual.
To replace the filter, first put the car on a jack. Drain the transmission fluid, and remove and clean the pan. Then, put a new gasket seal on the pan before replacing it.
Next, remove the old filter. It may be bolted in place, but you can generally get it out with a screwdriver. There may be snaps instead of bolts, which will make removal much easier. Take your new transmission filter and put it in the old one’s place. Bolt or snap it in place. Then, put the transmission pan back in place, and add new transmission fluid. Be sure to dispose of the old fluid properly. Don’t throw it on the ground or down the drain. Talk to your local auto parts store to see if they’ll take it. If not, they’ll at least know who will.
If you’d rather not replace your own transmission filter, or are not quite sure you know how to do it correctly, call your mechanic instead. They’re trained in how to do it properly, and can avoid the problems that can arise from poor or incorrect installation—problems which can result in much more expensive repairs down the road.
However, whether you do it yourself or call a professional, the most important thing is that you take care of your clogged filter as soon as you notice a problem. A clogged filter is a fairly straightforward job for any mechanic. But the longer you wait, the worse things will get, and the more extensive the repairs will be. So go sooner, rather than later. You’ll be glad you did.