What is Torque Converter? Definition, Parts, Types, Bad Symptoms

What is Torque Converter? Let us learn it with basic definition, parts, types, bad symptoms, etc. You may have heard of manual transmissions, where an engine is connected to the transmission by a clutch. In the event of a breakdown of this connection, the car might not be able to stop. A transmission without a clutch is uncoupled from the engine in an automobile with an automatic transmission. 

The answer lies in a marvellous device called a torque converter. It might be obvious from the name alone that it is completely technical in nature. In spite of this, this device has a lot of exotic features. One must learn more about this specifically designed car component that holds utmost prominence. 

What is Torque Converter? Definition

A torque converter is a type of fluid coupling used to transfer rotating power from a prime mover just like internal combustion engine to a rotating load. Torque converters connect power sources and loads in automatic transmission vehicles.

This component is often located between the engine’s flex-plate and the transmission. A mechanical clutch would be the equivalent location in a manual transmission.

While the stator is locked against its one-way clutch, fluid from the turbine’s curved vanes is deflected off the stator.  A torque converter increases torque when the output rotational speed is low, equivalent to a reduction gear. In addition to matching rotational speed, it multiplies torque without multiplying power, so it reduces power consumption.

Design of Torque Converter

Torque converters are solidly manufactured donut-shaped devices that connect engines and transmissions. Inside the device, there are two curved plates facing opposite directions. Fluid fills up the inner space of the device, transmitting power from the engine to the transmission.

It may seem that fluid-drive cars operate differently. Engines propel impeller turbines that transfer fluid to turbines, but in general, they propel the impeller turbine that propels it. Turbulence factor is reduced, heat generation is decreased, and energy transmission is enhanced when the blades are specifically manufactured.

For clarity, let us consider two fans facing opposite directions. When one engine is turned on, the second one transmission is automatically driven. The spin rate of both fan blades will be the same when their weights are similar. In the same way, the car’s fan blades work. Other examples are similar to torque converters, in which the stator assists in the transfer of the fluid back to the impeller turbine in order to increase the energy efficiency. A lock-up converter can also be purchased which locks the converter at corresponding RPMs and spins automatically with the engine.  

Parts of Torque Converter


In torque converters, the turbine transfers power from the engine to the transmission, making it the most vital component. Transmissions cannot receive power from engines if the turbine is not spinning. In order for power to be transferred, the turbine must spin faster than the engine.

Transmission input shafts are connected to turbines by splinted couplings. The turbine can spin independently of the transmission input shaft, thanks to this coupling. Power cannot be transferred unless the turbine spins faster than or equal to the engine speed.


The torque converter clutch or TCC engages and disengages the converter. When the engine is idling, the TCC prevents the converter from over speeding.


This component consists of a stationary vane placed in the center of the converter. Located between the pump and turbine, it is attached to the engine’s flywheel or flex-plate. Additionally, the stator controls the turbine’s rotational direction.

The stator vanes guide fluid from the pump to the turbine when the transmission is in drive. Turbines rotate in the same direction as engine crankshafts, so the wheels of the car are driven.  

Impeller Pump

Another crucial component of a torque converter is the pump. It circulates fluid through the converter by being attached to the impeller.  On the outside of the converter, the pump also creates a high-pressure zone.


As the turbine and impeller reach cruising speed, torque development slows down, and both are rotated at the same speed. An automatic transmission locks up the turbine to the impeller via the torque converter, which functions as a fluid coupling. By doing so, power loss is prevented and the vehicle rides smoothly. The impeller receives energy from the torque converter, which is connected to the engine.  When the movement and process of this operation vary, the shaking effect occurs.


Even though the impeller receives power from the engine, it does not rotate when the driver applies the brakes, such as during a stoplight. There will be no motion, but the vehicle does not stall.


In order to accelerate, the driver must remove their foot from the brake pedal and place it on the gas pedal. Eventually, the impeller starts rotating too fast and the turbine and impeller speeds vary more widely.  Therefore, this variation increases the vehicle’s acceleration by developing torque.  

Transmission Fluid

Torque converters rely on transmission fluid for their survival. As well as helping to lubricate moving parts, it also helps to transfer heat. In addition to providing a hydraulic link between engine and transmission, transmission fluid also acts as a lubricant.

How Does Torque Converter Work?

It is difficult to comprehend how fluid can move something as essential as a vehicle. Let us try to understand how a torque converter actually work.

  • The torque converter is controlled by the rotation of the crankshaft by circulating fluid around it.
  • In the housing, turbine blades rotate every time fluid comes in contact with them. This method can be used to measure the torque transmitted from the input shafts to the transmission.
how does torque converter work working
How does torque converter work working
  • As the crankshaft in the turbine housing rotates at the same speed as the torque converter housing, so does the flywheel in the torque converter housing.
  • A centrifugal pump pushes the transmission fluid into the turbine ribs, which, in turn, rotates the transmission or transfers torque to it.
  • Using a stator instead of a pump, fluid is directed back into the turbine, thereby increasing system efficiency.
  • Since the transmission oil pumps into the turbine at a slow speed when the vehicle is idling, very little torque is being transferred to the engine through the transmission.
  • Fluid moves faster from the pump to the turbine as the crankshaft spins faster and the flywheel spins faster, allowing the turbine to spin faster, allowing more torque to be transmitted.

There is still a great deal of mystery surrounding the torque converters inner workings. Although the mechanics are understandable, fluid mechanics experts should be able to explain the complicated calculations and engineering behind it.

Types of Torque Converter

Consolidated Vehicle Converter

Among the most popular torque converters in the industry, CVC offers reliable, yet affordable sealed torque converters. An industrial engineering production line is combined with bench craftsmen’s skilful expertise.

Pro-Torque Performance

In partnership with industry-leading manufacturer Pro-Torque Performance, Tran-star offers custom-built performance torque converters. Not only will racing fans enjoy the product’s quality, but also its speed.

It’s not just their unrivalled technology that has made ProTorque a popular builder of customer performance torque converters, but also their ability to match units to applications precisely.

Recon Certified Torque Converter

Every RECON Certified torque converter is warranted against manufacturing defects for four years and 100,000 miles upon purchase. 


In addition to torque converters, EXEDY also manufactures motorcycle clutches, manual clutches, and parts for agricultural vehicles, automobile products, and construction machinery. The company announced in January 2016 that it would expand its Mexican factory to produce more torque converters. Furthermore, torque converters for CVTs may be included in this expansion.

Yutaka Giken

Automobile parts are manufactured and distributed by Yutaka Giken. Among its customers are Honda Motor, Honda R&D, Honda Trading, Suzuki Motor, and ISUZU MOTORS. The company manufactures flat torque converters for passenger cars using precision stamping and bonding technology. In subcompacts and standard cars, it is widely used.


Powertrain components and systems are BorgWarner’s primary focus. Vehicle performance, fuel efficiency, vehicle stability, and air quality are improved by the company’s products. In 2016, BorgWarner employed 27,000 people. A turbocharger, a timing system, a thermal system, a thermostat, an emissions system, and the gas ignition technology are all developed by the engine segment. 

All-wheel drive vehicles and automatic transmissions are manufactured by the drivetrain segment.

ZF Friedrichshafen

As a design, R&D, and manufacturing company, ZF Friedrichshafen is well known in the automotive industry. Located in the United States and internationally, the company provides driveline and chassis technologies to automobiles and commercial vehicles. As well as plant equipment, the company offers construction equipment. Modern passenger cars with automatic transmissions use torque converters from ZF Friedrichshafen.


Schaeffler offers high-precision products for transmissions, engines, and chassis, along with rolling bearing and plain bearing solutions, linear drive technology, and linear and direct drive systems under its brands INA, LuK, and FAG. As part of its February 2016 release, the company introduced its high voltage hybrid module P2. For existing vehicles in the American market, this module is equipped with an integrated torque converter.

Problems of Torque Converter

Lagging & Surging

In addition to power loss, there is lagging as well. A torque converter problem can result from erratic converter fluid pressure or flow if your machine lags during operation, for example, when it cannot maintain a constant speed, power, or lift.

There may be times when the high fluid pressure in a torque converter causes more power to be transmitted than normal. The machine’s power will lag unpredictably as a result. There might be an isolated occurrence, or the engine may speed up and slow down periodically. If the engine is functioning normally, the torque converter may be to blame.

Clutch Slippage

You will notice this when the clutch slips after heavy acceleration, especially after hard acceleration.  While the engine is producing power, but not transferring it to the torque converter, it will appear as if the converter is losing power.

You can be up and running in no time with a simple clutch adjustment.  The master clutch assembly will be severely damaged if left untreated for too long, requiring its removal and replacement.  In order to save money, you must maintain your equipment and fix any problems as soon as possible.

Power Issue in Converter

It’s frustrating when you ask for power and get little in return. This can be exacerbated by a problematic torque converter, which converts horsepower to torque. It is important to allow enough time for converter pressure to form in order to get the best power from a torque converter. You would not get the power you need if it does not.

In the event of a torque converter failure, the transmission can receive too much or too little fluid, resulting in transmission gears slipping. There will be a loss of power for the machine as a result. You may need to replace the torque converter if the machine does not have the power it should have. A loss of fuel economy would be a sign of this in cars. Make sure the fluid is not dirty or low. In some cases, the system just needs to be refilled with fluid.

Torque Converter Symptoms

It acts as a link between the engine and the transmission by acting as a hydraulic pump. To create a fluid coupling, and to provide the transmission with the fluid pressure, the torque converter uses vanes, similar to a turbine, that act on the transmission fluid within the unit.

Turbine blades operate by generating power through the shaft to which they are attached. Torque converters have the advantage of transmitting power even if the input and output shafts are not synchronized, which is an advantage over other types of fluid couplings. It is thus ideal for automotive applications in which engine speed varies greatly, but wheels rotate at a relatively constant rate.

Symptoms of Bad Torque Converter

The torque converter is not easy to diagnose without disassembling the transmission but there are a few symptoms to look for. Torque converter failures are characterized by shudders, dirty fluid, shifting gears when the engine is at high revs, and strange noises such as clicking or purring.

The symptoms of a bad torque converter include transmission overheating, leaks, and noise. The torque converter most likely needs to be replaced if you experience any of these problems. You can complete this repair in about an hour if you have basic mechanical skills.

Symptoms of a failing torque converter can be similar to those of a failing transmission, so it should be included in a diagnosis of suspected transmission problems. In the case of a failed transmission that released metal salts and friction-material particles, you should also replace the torque converter, since the debris cannot be fully flushed out.


If your car is overheating, the fluid pressure in your torque converter may have dropped and there is a problem with the fluid pressure. Power cannot be transferred from the engine to the transmission if a converter overheats.

Consequently, the transmission suffers from poor throttle response and excessive wear and tear. Overheating can also be caused by low fluid levels or a defective magnet.


Transmission overheating is another sign of a bad torque converter. It means the fluid in your transmission is getting too hot and not cooling properly if it is overheating.

Transmission components can be seriously damaged by this, so it’s crucial to fix it as soon as possible.

Transmission overheating can be caused by a few different things, so it’s important to consult a qualified mechanic to determine the cause.


The most common transmission problem is overheating, which can be a real headache. You can help prevent overheating by keeping your transmission cool and preventing it from occurring in the first place.

  • A clean and full transmission fluid is one of the best things you can do. This is a simple fix that can make a big difference if your transmission fluid is dirty or low.
  • Maintain a regular transmission fluid level by topping it off if necessary.
  • In addition to adding a transmission cooler to your vehicle, you can also help prevent overheating. Heat is dissipated from the transmission by a transmission cooler, which keeps it cooler and prevents overheating.
  • In the event that your transmission is already overheating, you can try a few different remedies to solve the problem. A simple solution would be to let the transmission cool down before driving again. As a result, the transmission fluid will circulate and cool down.
  • It is likely that your transmission will need to be repaired or replaced if the overheating persists. If a qualified mechanic diagnoses the problem and recommends treatment, the issue can be resolved.
  • Overheated transmissions can be repaired in some cases, but they may need to be replaced in others.

Transmission Fluid Contamination

Fluid used in automatic transmissions (ATF) is used in torque converters. Contaminated fluid can damage the parts inside. A worn stator bearing or damaged turbine fins can result from this.

There may be damage to the converter or the gearbox itself if there is a large amount of black sludge or dirt in the fluid. You can check the oil again after driving around for a while after changing the fluid. Having a professional check your car if the problem persists is a good idea.


A bad torque converter can also cause transmission fluid to leak. Leaking transmissions indicate damaged seals or gaskets that need to be replaced. A qualified mechanic can perform this relatively easy repair.


The first thing you should do if your transmission is leaking is check the fluid level. It may be that the fluid is leaking out if the level is low. You can check the seals and gaskets for leaks as well.

Slipping Transmission

A damaged rib or bearing in the torque converter can cause the transmission to slip out of gear or delay a shift because it converts engine torque to hydraulic pressure.

It is also possible for the transmission to slip due to an insufficient or excessive amount of fluid. Also, your car’s fuel consumption may decrease and acceleration may be lost. Before going to a store, make sure your fluid level is adequate.

A low torque converter output pressure will starve the transmission and cause it to slip. When driving, you may notice a general loss of power, especially when accelerating. Prevent premature wear of the transmission friction material by addressing this as soon as possible. The fluid-coupling effect, which is inherently inefficient, can also cause slippage if the converter clutch fails to engage fully.


Slipping transmissions are one of the most common symptoms of bad torque converters. In slipping transmissions, the engine revs but the vehicle does not move, or the vehicle moves but the engine speed stays the same.

The torque converter may not be locking up properly, which can cause this problem.

In order to determine the root cause of a slipping transmission, you should consult a qualified mechanic.


Check the fluid level and condition whenever your transmission slips. If the fluid is low or dirty, there could be a problem. Check your transmission filter to see if it needs to be replaced.

Slipping transmissions can also be caused by torque converter problems. A torque converter that does not lock up properly can cause the transmission to slip.

You can fix this problem by having your vehicle checked by a qualified mechanic who can replace the torque converter if necessary. If your transmission slips due to a worn clutch, you may be able to replace it yourself. A mechanic with experience should attempt this problem.

Broken Needle Bearings

Needles are used in the impeller, turbine, and stator to allow them to rotate freely. These rotating components are separated from the converter housing by bearings. Due to metal-to-metal contact or grinding, you will experience decreased performance, strange noises, and metal parts in the gear fluid if these bearings are damaged.

High Stall Speed

Engine stall speeds are the engine speeds which are high enough to enable the torque converter to transfer power to the transmission. When transmission power is prohibited, the converter stops increasing the engine speed.

An engine’s rotational force cannot be transferred correctly to hydraulic pressure if the torque converter is defective. In this situation, the transmission is slower to respond to the motor being switched on, causing the lock-up speed to increase. A stall speed test can be performed as follows. It is important to know how fast your vehicle stops before you begin, usually between 2000 and 2500 RPM.

Dirty Transmission Fluid

It is possible to end up with contaminated transmission fluid if you do not drain the torque converter properly.

It converts the engine’s rotational force, or torque, into hydraulic power that turns the input shaft of the transmission. Over time, this heat can cause transmission fluid to break down and become dirty due to this process. There can be several problems caused by this.

Dirty transmission fluid can also be caused by a leaking torque converter. Transmission fluid can leak out if the torque converter seals breaks, allowing dirt and debris to enter.

Unusual Sound

When a torque converter begins to fail, it often emits strange noises. An example of a sound you might hear is the whirring of bad bearings, or the clinking of a broken turbine fin.

It is possible for your torque converter to make various noises when it goes bad. When the power steering pump is low on fluid, you might first hear a whine. When damaged, a series of clutches within the stator can cause a rattling noise within the assembly. If you are idling in park, the noise will be light, but if you shift into gear, that noise will increase in volume and frequency, which is your converter’s death knell.


It is also common for a bad torque converter to be symptomatic of noisy transmissions. A worn bearing or a damaged clutch could be responsible for transmission noise. The repair can also be done at home since it is relatively easy.


Identifying the source of the noise is the first step. You will need to replace the torque converter if the problem comes from it. If you have the right tools, you can do this repair at home fairly easily. There are a few basic tools you’ll need, including a new torque converter and a transmission jack.

  • It’s necessary to replace the clutch if the noise comes from it. Professionals should handle this more difficult repair. To access the clutch, you must remove the transmission.
  • In this case, you should leave it to a professional since this is a complex repair that requires special skills. It is also common for torque converters to cause noisy transmissions.
  • It is possible that your transmission is making noises because the bearings are worn down or the clutch is damaged. Home repairs can also be done with this relatively easy repair.

Less Fuel Economy

There are several ways in which a bad torque converter can decrease fuel economy. An engine with a bad torque converter will drag more.

  • Engines can work harder than necessary when the torque converter isn’t functioning properly. Fuel economy can be decreased as a result of increased drag.
  • Another issue with a bad torque converter is that it can lead to transmission slippage. Fuel economy can be decreased if the engine revs higher than it should.
  • Last but not least, an overheated transmission is caused by a bad torque converter. As a result, transmission efficiency can be reduced and eventually the transmission may fail. As a result, fuel economy will be reduced.

Gear Shift Problem

Torque converters can cause shifting problems if they are not functioning properly. Transmissions are powered by hydraulic energy, which is converted from engine rotational energy by the torque converter.

  • Shifts can also be soft or delayed when the converter’s pressure output is lowered. The transmission will not shift and engage properly, so you won’t feel the nice, crisp feel. 
  • If your engine speed is higher than usual, then you may find that increasing the pressure from the converter will increase the likelihood of the transmission shifting into gear and engaging when starting.
  • The torque converter can cause transmission slippage and erroneous shifts if it cannot perform its duty effectively. Engine stalling can also be caused by a faulty torque converter.


At around 30 to 45 mph, the torque converter may shudder when the lock-up clutch fails. There is a very noticeable bumpy feeling and it usually feels like driving over lots of small bumps.

A torque converter with inconsistent output can cause the transmission to increase and decrease vehicle speed without simultaneous adjustment of the throttle as the hydraulic pressure changes. A vehicle that is in this condition can be dangerous to drive, and you should not drive it until it has been repaired. There are times when this variation can feel like a shudder, though the transmission mounts should be inspected and repaired or tightened as necessary before looking at the torque converter.

This feeling is often caused by worn lock-up clutches when the converter switches to direct drive. This feeling can last for a short time and then stop abruptly. If this occurs repeatedly, however, you should have your transmission inspected.

The reason behind Torque Converter Failure

A torque converter can fail for a number of reasons. When your transmission fluid is dirty or low, the torque converter can overheat and fail.

The failure of a torque converter can also be caused by a clogged transmission filter. In addition to physical damage caused by a car accident, excessive wear and tear can also lead to torque converter failure.

Broken Torque Converter Seals

Transmission fluid is kept in torque converters by torque converter seals. Transmission fluid can leak if these seals are damaged. 

The torque converter can fail if there is a loss of hydraulic pressure in the converter. Transmission components, including torque converters, can be damaged by leaking transmission fluid. You could eventually lose your transmission if you ignore a leaking transmission fluid issue.

Transmission Fluid Degradation

Degradation of transmission fluid is one cause of bad torque converters. The torque converter can become clogged with debris when the transmission fluid breaks down. 

A torque converter that is clogged with debris can lose power and efficiency if it can’t function properly.

A qualified mechanic should inspect your transmission fluid immediately if you suspect it may be degraded. It is also important to nip the problem in the bud before it worsens, such as transmission slippage.

Low Transmission Fluid

A bad torque converter can definitely be caused by low transmission fluid. The gears can grind and eventually break when the fluid level is too low. It will eventually cause a torque converter to fail completely because the torque converter will not work properly. Keeping an eye on your transmission fluid levels and topping them off as needed will prevent any problems down the road.

Damage Clutch Solenoid

Transmission fluid is kept in torque converters by torque converter seals. Transmission fluid can leak if these seals are damaged. Torque converters can fail due to a loss of hydraulic pressure.

Transmission components, including torque converters, can be damaged by leaking transmission fluid. You could eventually lose your transmission if you ignore a leaking transmission fluid issue.

Tear & Wear

There is wear and tear on the torque converter. The reason is that it is continuously exposed to high temperatures and pressures. It is possible for the converter to break down and fail over time as a result of these conditions.

Despite its importance, the torque converter is a part of the car’s transmission that can wear down over time. Torque converters can become ineffective over time, resulting in transmission problems. 

Having your vehicle inspected by a qualified mechanic is important if you notice any transmission problems.


The torque converter is subjected to increased wear and tear when your vehicle is overloaded. In some cases, the converter may even fail completely. It is important not to exceed the weight limit of your vehicle in order to avoid this. When carrying a heavy load, avoid sudden stops or starts.

Replacing the Torque Converter

It is first necessary to remove the transmission. It is possible to do this with a transmission jack. The torque converter needs to be disconnected from the engine once the transmission is removed.

An impact wrench and socket set will be needed for this task. The converter can be removed from the vehicle once it has been disconnected. Last but not least, the converter needs to be installed. It must be connected to the engine and then the transmission reinstalled.

This will require a transmission jack once again. It should be fine once everything has been reinstalled.

  • Make sure the battery is disconnected. Then you can work on the vehicle without risking any electrical shorts.
  • Fill a catch pan with transmission fluid after removing the dipstick. Keep enough fluid on hand in case you need to replace the fluid when you’re done.
  • The torque converters bolts are secured to the flex-plate by bolts. Sockets or wrenches are needed for this.
  • Ensure that the torque converter is well separated from the flex plate by carefully pulling it away. Do not force it, even if there is some resistance.
  • Both the converter and flex-plate gasket surfaces should be cleaned. Installing the new converter will be easier if you do this.
  • Reverse the removal and installation of the new converter. When connecting the battery and adding new transmission fluid, make sure all bolts are tight and there are no leaks.

Torque Converter as a Transmission Part

A torque converter is similar to a clutch in a manual transmission vehicle. Fluid transfers power instead of a manual transmission, preventing stalling and transferring power to the transmission.

Press the accelerator for two to three seconds while pressing on the brake pedal. You could blow out the transmission if you exceed five seconds. Stall speed is the RPM at which the engine maxes out.

Hydraulic Torque Converter

It uses liquid transmission to generate rotary motion or torque turning power. Hydraulic power transmissions come in two types, one is Hydrostatic & another is Hydrokinetic.


Motion is created by using pressure energy from the liquid.  


In hydraulic couplings, motion is created by using the fluid’s kinetic energy.

There are two rotatable shafts connected by hydraulic couplings. This motor has a vaned impeller which is mounted on a drive shaft, and the impeller and runner are located in the liquid-filled container. If there is no resistance to the driven shaft’s rotation, then the driven shaft will rotate at the same speed as the drive shaft. Upon placing a load on the drive shaft, it slows down and a turning moment will be created on both shafts at the same magnitude rate.

The driven shaft speed is 3% less than the driven shaft speed when the normal load is placed in the hydraulic coupling moment. A powerless connection exists between the impeller and runner, so no vibrations or shockwaves are created.

Uses of Torque Converter

Its extensive performance makes it suitable for a wide range of applications. 

  • Marine propulsion systems can easily be implemented.
  • The automatic transmission can benefit greatly from it.
  • Winches, drilling rigs, and conveyor drives are frequently used in the automotive industry.
  • Applied to modern forklifts as well as railway locomotives in the construction department.

Now, don’t be confused with Fluid Coupling, it is not the same. Let’s see a brief for basic understanding.

A fluid coupling provides a controlled soft start-up, reducing shock loads and protecting surrounding equipment. Using these couplings, you can control the torque as well as the speed.

In hydrodynamic couplings, one shaft is coupled to another by means of fluid transmissions, also known as fluid couplings or hydraulic couplings. In the automotive, marine, and power transmission industries, it is used in transmission systems.

Difference between Torque converter & Fluid Coupling

Sl .NoTorque converterFluid coupling
1.There are three main components in a pump: a stator, a turbine, and a pump.Impellers and runners are the main components.
2.Essentially, it is a unit for multiplying torques.The purpose of it is to connect members who are driving and driven.
3.There is a pitch to the turbine blades.A blade is nothing more than a fin.
4.A clutch serves as an automatic gearbox that increases torque as an automatic clutch.As an automatic clutch, it fulfils its purpose.
5.At highway speeds, it is not as efficient as fluid coupling, but under load, it performs slightly better.Highway speeds make it efficient.
6.To eliminate the slight efficiency loss at highway speeds, automatic clutches, which are mostly fluid flywheels, are usually used in conjunction with it.There is no friction clutch to assist it.
7.There is no locking up and the flow of oil never stops. When centrifugal force on both members is approximately the same, the impeller and runner lock up and oil no longer moves.
Difference between Torque converter & Fluid Coupling

Difference between Torque Converter & Clutch

As torque converters adjust gear ratios based on engine RPM, they are great for low-end torque. As a result, it is ideal for heavy-duty or off-road go-karts. 

Regular clutches maintain the same gear ratio exclusively.

The main difference between centrifugal clutches and torque converters is that centrifugal clutches tie the engine and transmission together, while torque converters allow the engine and transmission to work independently.

Torque converters are similar to clutches in manual transmission vehicles. In contrast to manual transmission vehicles, this vehicle uses fluid to transfer power to the transmission, which prevents the engine from stalling and allows the transmission to change gears.

Difference between Torque Converter & Gearbox

A torque converter increases torque while reducing speed, similar to a gearbox. As opposed to gearboxes, torque converters provide a continuous range of ratios from low to high, while gearboxes provide only a limited number of fixed ratios. From a place of rest, the vehicle gains speed and gradually decreases its gear ratio.

Torque converters do not require shifting mechanisms since torque increases with engine speed. As in a gearbox, there is no gear train. As opposed to gearboxes, it requires less maintenance and is compact. There is a narrow speed range where the torque converter is most efficient. A synchrocyclic gear train is used together with it.

Harmfulness of Bad Torque Converter

In short, a bad torque converter may cause transmission damage. Overheating can result in transmission failure if the torque converter does not function properly.

Furthermore, a malfunctioning torque converter can put additional strain on the transmission’s gears, resulting in failure. Transmissions can be damaged by a bad torque converter. Damage, overheating, friction, and transmission fluid degradation can be caused by bad torque converters. Transmissions can be further damaged if these problems persist.

Life Expectancy of Torque Converter

Torque converters are like other parts of a car in that they don’t last forever. Between 80,000 and 120,000 miles is the average lifespan of a vehicle, depending on how it is driven and maintained.

The torque converter will need to be replaced sooner if you regularly tow heavy loads or race your car.

To ensure that your torque converter lasts as long as possible, you should keep an eye on it and have it serviced as needed.

Depending on the make, model & types of your car, there’s no definitive answer to this question. To keep your torque converter in good condition, most mechanics recommend flushing it every 30,000 to 40,000 miles.

Causes of Faulty Torque Converter

Torque converter needle bearings can be damaged by excessive friction, resulting in torque converter failures. There may also be a problem with the clutch solenoids or seals. When a seal fails, fluid can leak and become contaminated. Torque converters can damage transmissions.

  • Torque converters can fail for a variety of reasons, but the most common is fluid leaks caused by faulty seals. It is possible for the converter to overheat from friction when the fluid level gets low.
  • It is also common for hydraulic power to be inhibited by clogs caused by dirt and debris in the fluid.
  • Last but not least, a bad clutch solenoid can cause a torque converter to fail.

Testing Torque Converter

There are several ways to test torque converters. It is possible to determine whether a torque converter is stalling by using torque converter test kits.

Torque converters can also be tested using a pressure gauge. This will allow you to determine whether the converter has built up enough pressure. Mechanics can assist you with the torque converter test if you do not have either of these tools.

The torque converter will be able to be checked by doing this. Torque converters can be tested in the following way.

Precautions Checking

To make sure the test is safe, ask your car’s or transmission’s manufacturer. A stall-speed test can damage most newer transmissions, as well as some older ones. Stall-speed tests shouldn’t last more than five seconds. Vehicles with anti-lock brakes or traction control should not be subjected to this test. Your check engine light will come on if you perform a stall-speed test on some electronic transmissions.

Car Preparation

Your torque converter should be cleaned and inspected before being tested. You should also chock your wheels and set your parking brake. You should install a tachometer that can be seen from the driver’s seat if your car doesn’t have one.

Pressing the Brake Pedal

In addition to pushing the brake pedal while pressing the accelerator, hold the accelerator pedal at the floor for two to three seconds. Avoid exceeding five seconds, or you may blow out the transmission. Stall speed is the maximum RPM the engine can reach.

Start Your Engine

Start your engine by pressing the brake pedal all the way to the floor. Make sure your transmission is in drive. Hold on to the brakes at all times.

If the torque converter lockup clutch fails, the engine can stall when the car is braked to a stop in one of three ways. In either case, it can never lock up, causing fuel consumption and radiator temperature to increase, or it can slip, causing constant engine speed surges.

Stall Speed Testing

You should repair or replace the torque converter if the RPM reading is lower than the specifications for your torque converter and engine. Having a high RPM reading indicates that your transmission is slipping and needs to be investigated.

Despite your best efforts, you can’t figure out what’s wrong with your car’s transmission. You might need to replace your torque converter even if your transmission is fine. On many older transmissions, you can diagnose torque converter problems by performing a stall-speed test.

Testing Bad Torque Converter

There are a lot of things that can cause torque converter issues, which is why it is so difficult to diagnose them. A technician can diagnose and repair the problem by assessing the symptoms before further damage is caused by the faulty transmission.

Here’s how to determine whether a torque converter is failing using a simple test:

Points below will show you how to conduct a torque converter test safely and easily.

  • Start the engine by turning the ignition key. Let the engine warm up for a few minutes before gently pressing the accelerator twice and revving it up. Press the brake pedal all the way and shift into drive when it returns to its idle state. Listen for lurching, clicking, and whirring sounds that indicate a converter problem.
  • Take note of whether the sounds occur as you shift through all gears, including reverse. Shifting gears with lurches or failures also indicates a problem.
  • If the vehicle lurches or makes any of the dreaded sounds, drive around for a while and note if the gears shift slowly or do not shift.

There are times when your car’s transmission acts up, and you aren’t exactly sure why it’s doing that, and we aren’t all car experts. 

There could be a problem with the transmission, or the transmission may be fine, but the torque converter may not be working. In many older transmissions, torque converter issues can be diagnosed by performing a stall-speed test. 

Merits of Torque Converter

Torque converters have the advantage of transmitting power even when the input and output shafts are not synchronized. Since the wheels must rotate at a relatively constant speed, it is ideal for automotive applications.

In addition to allowing the engine to idle without stalling the transmission, torque converters can also act as fluid couplings. Even when the input shaft is not rotating, the turbine will continue to rotate.

A torque converter can also provide a mechanical advantage, which means that it can multiply the engine’s torque. Towing or hauling heavy loads requires a lot of torque, so this can be useful.

Demerits of Torque Converter

This type of fluid coupling has several advantages, but it also has some disadvantages. The major drawback of these couplings is that they are typically less efficient than other types. Therefore, they can increase fuel consumption and make the engine work harder.

Transmissions with torque converters are also heavier and bulkier because torque converters add weight. Consequently, the transmission may become less responsive and more prone to overheating.

It is important to regularly service and flush torque converters to prevent damage from debris or dirt in the fluid.

FAQs on Torque Converter

Do you require Torque Converter in all cars?

As far as automatic transmissions are concerned, torque converters are almost universally used in light trucks and passenger cars. Typically, torque converters are not used in all transmissions in heavy trucks and construction equipment.
It is possible to connect the engine to the transmission with a fluid coupling; however, this type of coupling does not offer the same level of efficiency as a torque converter.

What to do when Torque Converter goes out?

There may be shuddering and even slipping in overdrive when the torque converter malfunctions. It feels like your car is vibrating when it shudders. It is possible for your car to vibrate even if you are not going very fast. It is very noticeable that the car lags due to the shuddering.

Is Torque Converter boost up your car?

With a higher stall torque converter, you will be able to accelerate more quickly. This is because you will be able to take off at the best rpm range, where you will be able to make the most power. Furthermore, you do not want to have a stall speed that is too high, which will cause the engine to overheat.

Is it ok to drive a bad torque converter Vehicle?

A bad torque converter shows a few telltale signs. Your car may slip out of gear or you may have difficulty shifting gears.
If you are driving at high speeds, your car might shake or vibrate, or your engine’s RPMs may be higher than usual.
If you notice any of these symptoms, you should get your car checked out by a mechanic as soon as possible. A bad torque converter can severely damage your transmission, so you should avoid driving with one if possible.

Can you briefly describe about torque converter?

An engine and a rotating load are driven by a torque converter, a type of fluid coupling.
Turbines and pump impellers are mounted on a common shaft to form the torque converter. Turbine blades are fed fluid from a sump by the pump impeller.
Torque converters are sealed units, and as such must be serviced or replaced as a whole. Shells made of two welded halves enclose the unit. Fluid leakage will occur if the welds fail in the outer or inner joint.

What is bad converter’s sound look like?

You can tell when something is wrong with your car by listening to its noise when you drive it for a long time. The vehicle will also emit a bad torque converter noise when the torque converter fails, a whining or whining sound like a power steering pump with insufficient fluid.

Wrapping it Up

You can have several problems with your car if your torque converter fails. A qualified mechanic should inspect your vehicle if you notice any of the symptoms listed above. The failure of the transmission can be caused by ignoring these issues.

To avoid further damage to your car, it’s important to have a qualified professional replace your torque converter.

Torque converter replacement costs may vary depending on the car’s manufacturer and model, but in most cases, they are between $500 and $1000.


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