6 symptoms of a bad torque converter

It is easy to mistake a bad torque converter for a problem with your car’s transmission. The challenge comes from the fact that the symptoms that indicate a fault are quite similar.

To that end, this article will provide you with 6 symptoms of a bad converter, so you do not have to make that mistake. While taking the vehicle to a repair shop will reveal the source of the issue; finding out on your own is not a bad idea. A bad torque converter cannot go unnoticed, so these signs are easy to recognize.

What are torque converters?

inside a torque converter

A torque converter operates as a device that multiplies the torque whenever the engine is at low rpm. It does this to keep the engine’s power output within the optimum range. This device sits between the vehicle’s transmission and the engine. As an ideal location from which the torque converter can carry out its primary function, it allows for power transfer.

Transferring the engine’s power to the car’s transmission is the other function that adds to the importance of this device. For more in-depth information on these devices, check out the article I have written specially on torque converters.

Factors that contribute to torque converter issues

Torque converter issues

The factors that lead to a faulty torque converter are a degraded torque converter clutch, a damaged torque converter seal, faulty needle bearings, and damaged torque converter clutch solenoid. These are the things to look out for to prevent a faulty torque converter constantly.

The degraded torque converter clutch

A torque converter clutch locks the engine and vehicle transmission to make them rotate at the same rate. This action is only required at certain times, and a faulty clutch will make it unpredictable. The car can remain in gear even when the vehicle stops. A faulty clutch can cause the converter to lock the engine and vehicle transmission when it isn’t required. This leads to the torque converter developing a fault if not repaired.

To better understand the clutch, you should read my article on the torque converter clutch.

Damage seal

The transmission fluid inside the device will leak if the seal keeping it inside the device gets damaged. Leakage of the transmission fluid will cause slippage, overheating, and higher stall speed in the car engine.

Also, due to the leakage, a seamless transfer of power from the engine to the transmission will be impossible. This is because the device will not be able to make the transfer due to the leaking transmission fluid.

Faulty needle bearings

Needle bearings are the device components that separate the turbine, impeller, stator, and converter casing. When these parts of the device are damaged, the separation becomes affected. This effect leads to noises during driving and the presence of metal chips inside the transmission fluid. The metal chips are a result of the contact between the components that were originally separated.

Damaged torque converter clutch solenoid

The solenoid comes as an electronic component of the torque converter clutch. Generally called the torque converter clutch solenoid, it takes the measure of the fluid pressure required and controls the fluid volume that enters the lockup clutch.

A damaged solenoid will always give the wrong measurement of the required transmission fluid. This effect can cause an abnormal increase in fluid pressures. So there can be too much transmission fluid coming into the clutch or too little. What this causes includes engine stalling and even poor gas mileage. Now that you know what to look out for to prevent damage to your car’s converter, let’s take a look at the symptoms of a damaged converter.

Symptoms of a bad torque converter

Torque converter

These signs explained below are indicators that this device is faulty. As soon as you notice them, kindly take your car to the repair shop to replace the converter.


An example of shuddering is when you drive on a smooth road, and your car begins to shudder like you are on a rough surface. This might not be all the time – just occasionally, you should take note. This vehicle's behavior is that the torque converter is finding it hard to move into the direct drive smoothly. As a result of the lockup clutch not being able to enable the converter to carry this action out.


Overheating is another sign of a bad torque converter. You will notice the temperature gauge of the vehicle flashing the light of the transmission control unit. This is to call your attention to the fact that the car is overheating.

While other factors like slippage can also lead to overheating, it is not good for this mechanical device. The reason is that it will increase the wear of internal parts of the transmission. Also, the transfer of power from the engine to the vehicle’s transmission will become possible.


The primary cause of slipping in cars is insufficient or even excessive fluids in the car’s transmission. The converter ensures the shipping of the transmission’s gears by converting the engine’s torque into hydraulic pressure. Because of this, the device might slip out of gear if its bearing or fin gets damaged. Loss of acceleration in cars, as well as fuel economy reduction, are evidence of slippage.

Contaminated transmission fluid

Inside the torque converter, you will find a fluid called the automatic transmission fluid. This fluid aids the device in carrying out its functions properly. Contamination of this fluid includes the presence of grime or debris. If this is confirmed, it is an indication of a damaged transmission.

Since the transmission is connected with the converter, this contamination can affect the converter's various parts. Parts like the turbine’s fins and the bearings of the converter’s stator can be affected. Making sure that you have a high-quality fluid present inside the transmission all the time is a good way to prevent contamination. Do not forget that replacing the used fluid will save you lots of money.

Unusual sounds

Remember that damaged or faulty bearings will lead affect the positions of the fixed components of your converter. When these parts aren’t held in place, they contact each other and produce sounds. These unusual sounds come because of the metal parts sliding against each other. Clicking or whirring sounds coming from the car indicate damage to the turbine fin or bearings.

Increased stall speed

Stall speed refers to that point where the engine’s RPMs (rotations per minute) rise high enough for the engine’s power to get transferred to the transmission. The torque converter carries this transfer. When the device gets damaged, the transfer of power will no longer be smooth and seamless. As a result of this, the vehicle will begin to experience an increase in the normal stall speed.

What this means is that the transmission will take more time to engage the vehicle’s engine. The moment you take note of any of the signs mentioned above, do well to take the vehicle to a repair shop.

Key takeaways

The major points of the article are mentioned in this article; they are as follows.

  • Drivers can make the mistake of thinking the fault lies in the transmission instead of the torque converter.
  • Things that can damage a device include a degraded torque converter clutch, a damaged torque converter seal, faulty needle bearings, and damaged torque converter clutch solenoid.
  • A bad torque converter's symptoms are shuddering, overheating, slipping, contaminated transmission fluid, unusual sounds, and an increase in stall speed.

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