If you are into cars, you have probably heard about the torque converter before and the problems associated with it.
Torque converters can be found in almost all older cars with automatic transmission and also in many modern cars. This is probably one of the reasons why you have heard of so many failed torque converters.
In this article, you will find all information you need about the torque converter. You will find information about how it works, the most common symptoms and causes of a faulty torque converter, and how to test the torque converter. If you cannot find your question, simply comment at the end of the article.
Faulty Torque Converter Symptoms
There are several strange symptoms that can occur with a faulty or failing torque converter. Here is a list of the most common and noticeable symptoms you may have in your car.
1. Transmission Slipping
A very common symptom of a defective torque converter is that the transmission slips during acceleration. You can feel this when the engine revs up strongly on the gear drive while the car does not accelerate against the engine speed. Often you need to have a good feel for your car to detect slippage.
2. Rough Idling
Rough idling is another common symptom. If you feel that your idle is a bit jumpy and sometimes too low and sometimes too high, it could be a problem with the torque converter. If the torque converter is faulty, many different pressures can be generated inside the converter, which can cause rough idling.
3. Rough Acceleration
Rough acceleration is also a known symptom when it comes to defective torque converters. This can be caused by different pressure peaks in the torque converter as well as by the fact that the torque converter slips, as already mentioned. If you feel that you are experiencing rough acceleration, check your RPM meter to see if it jumps a little when accelerating. If this is the case, a faulty torque converter is probably the cause.
4. Car won’t move in drive or reverse
If your car does not move at all in drive or reverse gear, a completely failed torque converter could be the cause. However, a car that does not move in gear can be caused by many different things, and it should be properly diagnosed before replacing anything.
5. Transmission overheating
If the torque converter slips while driving, this can lead to unnecessary heating of the transmission fluid, which at some point can even become so hot that it boils. A slipping torque converter will wear out the transmission very quickly. In some cases, you may have temperature sensors that cause the transmission control unit light on your dashboard to flash, which is an indicator that your torque converter is slipping.
6. Noises from the transmission
Check whether you can feel or hear strange noises from the torque converter both when idling and accelerating. Listen in the middle of the car under the gear lever to see if you can hear knocking or other strange sounds. If you hear any noises, lift the car up and check if other things could be causing the noises before replacing the torque converter.
What is the function of the torque converter?
The torque converter is the unit that gently transmits power from the engine to the transmission gears. In short, the torque converter is filled with transmission fluid and has a “fan” or turbine-like unit inside. The more it rotates, the more pressure it creates inside the unit, and the more power is transferred from the engine to the transmission. For example, if you run two fans against each other and start one of the fans, the other fan will also start rotating, but not directly at the speed the other fan has. This is exactly how a torque converter works.
As you can probably figure out, this gives you a very smooth power transmission between the engine and the wheels. However, there are also some negative aspects. Because there is no direct connection between the engine and the transmission, you lose some power from the engine and the engine becomes less efficient.
This is often the reason why older transmissions have a higher fuel consumption than cars with manual transmission. To avoid this problem, newer automatic transmissions use a traditional manual transmission with a wet or dry clutch, and they let a robot control the shift and clutch operations for you. These are called DSG transmissions and are much more efficient than traditional automatic transmissions.
Common Torque Converter Problems
When it comes to torque converters, there are some common problems that can be encountered. In general, the torque converter is not a very advanced part of older vehicles, and there are not many parts that could fail. Sometimes you can find cheap full replacements for torque converters, in which case it is often not worth taking it apart and replacing different component parts; rather, it’s cheaper and quicker to replace the whole thing.
Bad Torque Converter Bearings
A very common problem is that the bearings of the torque converters are worn out. This does not cause slippage or other problems with the transmission but can cause bearing noises from the transmission. If you hear bearing noises from the transmission, check the transmission fluid, and see if you can see metal parts inside the transmission. If you find metal parts, they are probably from a defective torque converter bearing.
Damaged Converter Seals
A faulty seal of the torque converter will cause the transmission fluid to leak out of the torque converter and thus the pressure inside the converter will be lost. Low pressure inside the torque converter will cause slippage, overheating, and other strange symptoms. This is actually one of the most common problems when it comes to a faulty torque converter.
Faulty Torque Converter Clutch Plate
There are several clutches in a torque converter. If the torque converter is locked in the drive and idling does not release the transmission, you most likely have a problem with the converter clutch. A faulty torque converter clutch can also cause other symptoms such as slipping and rough acceleration.
Faulty Torque Converter Clutch Solenoid
The torque converter clutch solenoid is a common part that fails within the automatic transmission. The solenoid valve controls the fluid pressure of the hydraulic transmission, which enters the lock-up clutch. This can cause various symptoms such as slipping, overheating, and rough acceleration.
So now that we know how a torque converter works and know the most common symptoms and causes, it is time to examine how we can actually repair our torque converter and which parts we should replace. Here are some of the solutions that could be used to solve problems with your automatic transmission.
Change the Transmission Fluid & Flush it
The first thing I always do when there are problems with the transmission is to change the transmission oil and inspect it. Drain the transmission oil and check it for signs of metal parts inside. If you find metal parts, you most likely have worn torque converter bearings. Also, check the color of the transmission oil: If it’s brown or almost black, it’s definitely time to change the oil and the filter, if the car has one. Changing the transmission fluid is quite cheap compared to a torque converter problem and can solve a lot of different problems. So my recommendation is always to replace the transmission fluid first and maybe even flush the transmission if the oil is really worn out.
Replace Torque Converter Bearings
If you find metal parts in the transmission fluid, it is time to remove the transmission from the engine and visually inspect the bearings inside the torque converter. Metal parts may also come from other failed parts inside the transmission, but most often they come from the torque converter bearings and should be inspected first.
Replace Torque Converter Seals
If you have a slipping torque converter and you have changed the transmission oil and filter and even performed a transmission flush, it is time to remove the transmission from the engine and inspect the seals on the axle into the transmission. Here is a video of how to replace the seals inside a transmission.
Replace the Torque Converter Clutch & Solenoid
If you have a lock-up problem or your transmission is in direct contact with engine RPM in all gears, it is time to visually inspect the torque converter clutch and solenoid. To check this, you must disassemble the torque converter.
Replace Entire Torque Converter
In many cases, the best idea is to replace the entire torque converter. Many cars have relatively cheap torque converters, and it is not really a good idea to replace certain parts in them, because it will not only take a lot of time but in some cases, it will actually cost you more. It is not recommended to buy a used torque converter, because you will never know how old and worn it is, and since replacing the torque converter is not very easy, it is no fun to do the job twice. If you are looking for a new torque converter for your car, I can recommend you to look at them here: Torque Converters on Amazon
What color is the transmission fluid?
Normally all automatic transmission fluids are red when they come from the manufacturer. However, the color of the transmission fluid can tell us a lot about the condition of the transmission. You could check the transmission fluid on the level stick and apply it to a white sheet of paper to make the color more visible. However, it is best to remove the transmission fluid from the pan. This way you can also check if you find metal parts mixed with the oil, which could be a sign that your gearbox or torque converter is damaged. Here is a table with the most common gearbox colors, and what this means for the condition of the fluid:
|Dark Brown||Worn out - Replace the fluid|
|Brown||Slightly Burned - Replace the fluid|
|Dark Red||Okay Condition|
|Pink||Water mixed with the fluid|
How to Test a Torque Converter
There are not many things you can do to test the torque converter without taking it apart. But there is a way to check the torque converter for signs of wear. Here is a method I usually use to check for problems with the torque converter.
1. Start the engine and let it warm up
First, you should start the engine and let the transmission oil warm up to around 40 degrees. This can take a long time, and it is recommended to check the temperature of the transmission oil with a diagnostic scanner to make sure that the transmission oil is warm. When the transmission oil is warm, it is time to move on to the next step.
2. Move shifter into gear
Now you can try to apply the drive gear and listen carefully if you can hear any signs of noise from the torque converter. The torque converter should move the car forward with just a light touch of the accelerator pedal. Shift between the other gears, (Drive and Sport, if you have it) to see if you can hear any other sounds from it. If everything seems to be fine, you can go on to the next step.
3. Test drive
Now it’s time for you to drive the car at a higher speed. Keep an eye on the tachometer and speedometer. If the car revs up significantly without actually accelerating, the torque converter is slipping. All older automatic transmissions slip a bit when accelerating, but if you have owned the car for a while, you probably know how much it should slip. If you are not sure, have a mechanic test drive your car and see if he hears any noise or feels a slipping.
Where is the torque converter located?
The torque converter is located between the engine and the automatic transmission. To diagnose it correctly and to carry out a visual inspection, you must remove the transmission from the vehicle and the engine. Some older American cars have a cover plate that you can remove to inspect the torque converter. But even with them, you will not see much because the torque converter is a sealed unit.
I do always recommend to remove the torque converter from the transmission to diagnose it properly.
Torque Converter Replacement Cost
If you have followed this guide and found that your torque converter is worn out and you want to replace it, you probably also know how much it will cost. This depends very much on whether you want to do the work yourself or have a mechanic do it for you. As we have already discussed, removing the gearbox from the engine to replace the torque converter is quite time consuming and can cause high labor costs. If you want to replace it yourself and feel that you have the knowledge to do it, you can save a lot of money.
A new replacement torque converter costs between $100 and $400, depending on the vehicle model and converter type. The labor cost to replace the torque converter is between $200 and $1000, depending on the vehicle model and the workshop that does the work for you.
To replace the torque converter, it will take between 3-12 hours, depending on your skills and experience.
Now there is not much more to discuss about torque converters. If you have further questions or would like us to add something to this article, please comment below and we will answer your questions as soon as possible. I hope you enjoyed this article!