How to Fix a Clogged Transmission Filter

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.

Your car needs water—but it has to be in the right place. In the radiator, it’s doing its job as usual. However, when it gets into other places—most notably, your transmission—then it can cause problems. How does water get into your transmission? What happens when the transmission gets flooded, and what can you do about it? Here’s what you need to know about when water floods your transmission.



How Water Gets Into Your Transmission


First, let’s address the issue of how water gets into your transmission in the first place. First, there could be a leak in your radiator. The water leaks out and gets mixed in with your transmission fluid. Check your transmission fluid. It’s supposed to be bright red. If it’s more of a milky pink, that means it’s diluted, and there’s water in there.


The water may also come in from outside. Your car is designed to withstand the elements, but that’s only as long as the water level doesn’t rise above a certain point on the car. If there’s a flood in your area, or you drive through a deep puddle, then water may reach the vent that keeps your transmission’s barometric pressure stable. If this happens, water can enter the transmission. Water may also enter through the dipstick tube, which then gets transferred into the transmission.


What Happens When Water Floods Your Transmission


Your transmission’s clutch plates use friction to transfer power from the engine. When water gets into the transmission—even a very small amount—it begins to dissolves the glue that holds the friction lining in place on the plates. Eventually, lining will come off the plates entirely, and the car will no longer be able to shift gears.


The mixture of water and glue then forms a gummy, white substance then ultimately spreads through the transmission fluid and makes the fluid difficult to flush out. Additionally, the water can simply cause the transmission’s metal parts to rust. If the problem isn’t caught quickly, it may require a complete transmission overhaul. All-in-all, water in the transmission is one of the most destructive things that can happen to an automatic car.


How to Get Water Out of Your Transmission


First, it’s important to spot the problem as soon as possible. If your car is in a flood, don’t start the engine before checking the transmission fluid for water. If you start the car, the water will be pulled into the transmission itself, making it much harder to remove.


If you manage to spot the problem in time, before turning on your ignition, then oftentimes the transmission fluid can simply be drained and replaced. However, if the water gets into the transmission itself, then the process is more complicated. Flushing the transmission may require several dozen quarts of fluid.

If you’ve been driving your car for a while with water in the transmission, then the problem is likely even more serious. The transmission may need to be replaced entirely.


As soon as you notice or suspect that your car may have water in the transmission, get it to a mechanic immediately. Have it towed if possible, rather than driving it, to reduce further damage. It’s a difficult, and often dangerous problem for your car to have, as well as, in most cases, an expensive one. But if you can spot the problem quickly and get it taken care of right away, you can minimize the damage and, with a bit of know-how, your car can be made good as new again.


When your car won’t go into gear, it can cause serious problems. What’s the trouble? It could be any number of things, depending on whether you have a manual transmission or an automatic transmission. Here’s a rundown of some of the possible problems, and what to do about them.


Manual Transmission Gear Problems


If you drive a stick shift, you may find that when you press the clutch, the gear shift still won’t move. The problem might be that the clutch is simply worn out. After a while, there’s no longer enough friction to transfer power from the engine to the wheels.


On average, the clutch on a stick shift wears out every 60,000 miles or so—depending on how and where you drive it. Fortunately, replacing it is a fairly routine procedure, which your mechanic should be able to perform relatively quickly.


There also may be an issue with the clutch master cylinder, and the hydraulic fluid contained therein. If the clutch goes all the way to the floor, then this may be the problem. If the cylinder leaks, eventually there won’t be enough hydraulic fluid to put the car into gear. In this case, the clutch master cylinder will need to be replaced.


Automatic Transmission Gear Problems


Automatic cars can have problems shifting into gear as well. In this case, there’s a good possibility the issue is an electronic one. Most of the mechanisms that tell a car to shift gears automatically are electronic, rather than mechanical. If the electronic signals aren’t being sent or received properly, it can keep the valves that control the flow of transmission fluid from opening or closing—which then keeps the car from going into gear.


Or the issue could be with the shift interlock mechanism. The mechanism is designed to keep you from accidentally shifting to Neutral or Park while the car is in motion. As you’re no doubt aware, you can’t put your car into Park unless the engine is running and both the break pedal and the button on the side of the gear shift are being pressed.


However, if you’re doing all of that, and the car still won’t shift into drive, try pressing the shift lock release button. It’s a small button, usually right next to the gear shift. There may be a small covering over the button, to prevent it from being pressed accidentally. Remove the cover and use a small, narrow object, such as a key or a screwdriver, to press the button. Then, depress the brake and shift gears as you normally would.


If this doesn’t solve the problem, or if the gear shift continues to lock going forward, then talk to your mechanic. You may need a new brake pedal position sensor, or there may be a transmission problem.


Transmission Fluid


This is an issue that can plague either a manual OR automatic transmission. The transmission fluid is what allows the gears to shift smoothly. Over time, dirt, grease, and other contaminants can build up in the fluid, causing it to turn from bright red to a brown or black sludge. This sludge is hard on your gears, and should be flushed out and replaced with new transmission fluid. As a general rule, replace your transmission fluid every two years or 30,000 miles.


There may also be a leak, which means there’s not enough fluid in your transmission—which also wreaks havoc on your gears. In this case, your fluid needs to be replaced—as soon as the leak is repaired, of course.


With regular upkeep to your vehicle, and regular service to your transmission when needed, you can prevent a lot of these problems and keep your gears shifting smoothly. Talk to your mechanic to see what your car needs to help it continue running optimally, and avoid costly repairs.

You should flush your transmission every 30,000 miles or so, draining the fluid and replacing it with new. 30,000 miles can be hard to keep track of, though, particularly as it may take three or four years to get there. And in some cases, you might need the change sooner. How do you know when your transmission needs to be serviced?

Here are five signs that you need new transmission fluid.



  1. Grinding Noises. If you hear a grinding noise in your transmission as you’re driving, it may indicate a couple of things. Your transmission fluid may be low, in which case it should be replaced. Or there may be a buildup of dirt, grease, and other contaminants, in which case, the transmission needs a flush. Check your transmission fluid levels, and notice what color the fluid is. If it’s red, it’s fine. If it’s brown or black, you need a flush.
  2. Leaking. When you pull out of your driveway or garage, do you see dark, oily spots on the ground where your car just was? If so, it’s a sign that your transmission fluid is leaking. First, you need to get the leak repaired as quickly as possible, to avoid further damage. Then, you’ll need new transmission fluid, to replace what’s leaked out.
  3. Slipping or Other Gear-Shifting Problems. Does your car slip in and out of gear? Does it have trouble going up or down steep hills? Maybe you’re having trouble shifting from one gear to another, with shifts coming too soon or too late. If this is happening to you, then you may not have enough hydraulic power. And one of the main causes of a lack of hydraulic power, is your transmission fluid. Just as with unusual noises, the cause may be a lack of transmission fluid, or simply that the fluid is dirty and needs to be flushed. Either of these issues can lead to gear slipping—which makes driving dangerous, and should be looked at and fixed as soon as possible.
  4. Surging or Stalling. If your car surges forward (or backward), seemingly at random, then it’s a sign that your transmission fluid may have become dirty. Alternately, if your car accelerates too slowly, and seems non-responsive, particularly when the light switches from red to green, this may also indicate a problem with your transmission. Finally, if your car likes to stall when you shift gears, then your transmission fluid may be overburdened with contaminants. In each of these cases, a change in transmission fluid may be necessary. Check the fluid, or have your mechanic take a look.
  5. The Check Engine or Transmission Warning Light Is On. The Check Engine light may indicate a number of things, but transmission problems are definitely among them. If the Transmission light specifically goes on, that’s an even greater indicator that you may need to replace your fluid. Whatever the problem may be, when a warning light comes on, get it checked out as soon as possible to determine the issue, and have the car serviced.

These are the major signs to look out for when your transmission fluid needs to be changed. If you notice any of them while you’re driving, don’t just let them go. Get them checked out immediately, to determine the problem and get it fixed. Changing transmission fluid is a fairly standard and inexpensive automotive procedure. But the longer you drive with low or dirty fluid, the more damage it will do to your car, and the more serious the repairs will be later on. Get it taken care of now, and save yourself the hassle (and the expense) later on.