Bad Torque Converter – Causes And How To Test It

| |

Do you know what gets an automatic car moving? You might say it’s as simple as pushing the pedal or moving the gearstick. However, this one part wouldn’t cross your mind. Torque converter comes on the top of the component list that is a part of the complicated process of getting your car on the move. A torque converter does all the hard work and makes your car function smoothly. 

How Does a Torque Converter Work?

Your vehicle is engineered thoroughly to form a connection between the engine and transmission. The process of power transmission is complicated and requires all the moving parts to be synchronized at the same time. In a manual car, the clutch gets this job done without killing your engine. Otherwise, you would have to restart the engine every time you stop your car.

For an automatic car, the clutch is replaced by the torque converter. You cannot deny its importance, especially when it comes to its function. It leverages the engine to work separately from the transmission. The torque converter is connected to the car’s flywheel with a highly durable case allowing both parts to move at the same speed. Inside the case, you will find four major components; pump, turbine, stator, and transmission fluid. The pump consists of small fins which form the connection. The transmission fluid moves inside the pump with this connection, regardless of the process. The fluid then gets into the turbine. The movement of fluid out of the turbine from a different entrance makes the transmission to spin; this is how your car starts moving.  

The transmission fluid doesn’t come in contact with the pump at any point in the process. This is possible due to the presence of a stator. It’s large blades, present in the center of the torque converter, redirects the fluid moving in and out before it could come in contact with the surroundings. You will find a modern iteration with a lockup clutch. This reduces slippage by combining the two halves of the torque converter, improving the efficiency of the car.

The torque converter receives small force while a vehicle is stopping slowly. This is how you can bring it to a complete stop by hitting the brakes with a small force. On the other hand, if you want to stop your car from faster speed, you would need to press the gas pedal to deliver a large amount of force. 

Do Vehicles With Torque Converter Have An Advantage?

All thanks to the torque converter that automatic transmission seems simple behind the wheels. Torque converter makes the drive much comfortable without stalling the engine. Your car will stop so smoothly and efficiently that the driving will become a pleasurable experience. The way it modulates the drive from the engine to the wheel is so smooth that the drivers take it for granted. 

The point where your engine is rotating much faster than the transmission, the torque converter turns into a force multiplier, making it at least three times the original amount. If both are rotating at the same or close to the same speed, a small amount of energy is lost. Therefore, a car with a torque converter gives you an edge when your car is accelerating.

Figuring out a Bad Torque Converter

Before the torque converter stops functioning at all, you will figure out some signs of a bad torque converter. 

  • The most obvious sign is when the gear begins to slip while the car’s transmission is taking place. You will feel like the car is moving over ice or up a hill loaded with heavy packages.
  • Even though you will be pushing the accelerator while the clutch is disengaged, your car will still lose the grip on the road. This could result in a forceful car jerk, and the vehicle will jump forward.
  • You will experience delayed acceleration as well as an inability to reverse.
  • The dirty transmission fluid is another sign of a bad torque. You will find black flecks present in the fluid, which has to be replaced immediately.
  • The vehicle will shudder at a lower speed, mostly at 40 mph. You will feel like dragging the vehicle over a series of small humps.    

The reason behind this is the inability of the torque converter to generate enough pressure for controlling the transmission fluid flow. The amount of transmission fluid affects the gear function, and this is how your vehicle starts moving in an unexpected manner. You can’t only blame the convertor for it; you should get your vehicle checked for high-quality fluid.

Once you face such problems, stop driving the car immediately and take it to the mechanic to replace it as soon as possible. Driving a vehicle would not only increase your problem, but it is dangerous as well. A bad torque converter will result in debris getting in other parts, causing damage to them. You would end up putting a lot of money if the car stops in the middle of the road. Don’t forget to add the cost of your vehicle being towed to the repair shop. You can also replace it if you feel a transmission lag while driving at a consistent speed.

How Causes a Torque Converter to Break?

A bad torque converter could result from various factors.

  • You will experience friction with clanking sounds if the needle bearings between the torque components are damaged. It doesn’t allow the turbine and stator to move freely.
  • If the torque converter’s seal is malfunctioning, you will witness the entire mechanism operating at a higher temperature. You will find a dirty transmission fluid at this time. The fluid might also spill.
  • A faulty clutch solenoid will result in uneven distribution of the fluid resulting in a bad torque.
  • The clutch in the converter doesn’t connect with the engine or transmission properly, which results in unnecessary friction.

How to Test a Bad Torque Converter?

To confirm that your vehicle is suffering through a bad torque, you need to put it through a test. However, you should be sure about the car’s transmission first. Some newer models are damaged by the test, so check your model before performing the test. Simply put, your car’s company, model, engine size, and its year of manufacturing to get an idea. Proceed with caution if you own the latest model transmission car.

After you have confirmed the transmission, you need to check the fluids. You need a good amount of clean transmission fluid before you run your car for a stall test. The third requirement on the checklist is the wheels and parking brake. Besides, get a tachometer that could be viewed from the driver’s seat as well. This way, you can easily collect the data required for this test. If you don’t have it, purchase one before moving to the next step.

Once you have checked everything, start your engine. Make sure that you are holding the brake pedal down because you will have to press the accelerator and the brake pedal at the same time after starting the engine. This is how you can measure the stall speed. Accelerate for two or three seconds but not more than that. If you go beyond five seconds, the transmission might blow out, causing damage to the vehicle. 

Measure the revolutions per minute (RPM) once the car engine is at its max stall speed. If the speed value is lesser than what the torque converter of your car requires, then the problem has just started, and you can fix it without any issue. However, if the value is higher than what is required, then the transmission would begin to slip now. The only solution you have now is to replace it. However, if the test is negative and the RPM value is the same as what is required, then try looking the cause of this problem in other parts of your car.

How to Get a Bad Torque Converter Fixed? 

Once you know that a bad torque is the cause of your car problems, the only solution you have is to get it replaced. However, don’t take it to your local garage mechanic. It is a delicate and complex car part that requires expertise to be handled. Don’t think about following a tutorial as there aren’t such videos on the internet, and merely getting this done on guess and check method can cost you a fortune.

Take your car to a professional who could actually solve this. You might have to spend a lot of upfronts, but you are taking a safer road in the long run. A broken torque converter takes $600 to $1000 to be replaced by a verified car mechanic. The part is not that expensive and costs only around $150 to $300. The expertise is what you are paying for. The entire assembly of the car would be taken out to replace a problematic torque, so you need to forget about your car for at least five to ten hours. You have to check for replacing the dirty fluid on your bill. Every shop has their own preference to charge the customer for fluid change.

Here, we have got you covered if you face any such issue with your vehicle. Stop at the mechanic shop as soon as you experience such warning signs of a bad torque and get it done by a certified mechanic to avoid future problems.  


How to Maintain Ceramic Coatings?