The torque converter plays a significant role in automatic transmission vehicles. It needs to be in good working order if you’re going to have a nice and smooth ride.
If it fails, you’re in trouble. The torque converter is a fluid or hydraulic coupling that converts rotating power generated by the vehicle’s rotating driven force to mechanical power.
The torque converter serves as an alternative to mechanical clutch disc, plate, and fork in automatic transmission vehicles. The torque converter is usually found between the transmission and the engine flexplate.
After reading this article, you will know the various parts of the torque converter, the symptoms of a bad torque converter, and how to fix torque converter problems yourself. You will be able to tell a bad torque converter vs. bad transmission.
What is a torque converter?
A torque converter is a key component in vehicles with automatic transmissions. It allows the transfer of power from the engine to the transmission and eventually to the wheels.
Though a torque converter may not be visible, this hidden device is crucial in delivering a smooth driving experience.
Picture the torque converter as a doughnut-shaped device that sits between the engine and the transmission. Inside, it’s filled with transmission fluid, the medium for transferring torque.
This fluid-based system allows your engine to keep running while your vehicle is stopped, such as when you’re idling at a traffic light.
Essentially, it replaces the need for a clutch in automatic vehicles, allowing for the same function of disconnecting and reconnecting the engine from the transmission, but in a much more seamless and automated way.
The torque converter offers a major benefit by preventing the engine from stalling when the vehicle slows or comes to a stop.
Additionally, it enables smooth gear shifts without requiring a clutch pedal, making driving easier and more comfortable for those with automatic transmissions.
Why Does It Matter?
When cruising at 2900 rpm in 6th gear, the transmission will be cruising at just under 50 mph, and the engine and the transmission will be rotating at almost the same speed. This is a pretty seamless integration.
Consider when a driver approaches a set of traffic lights in a manual-transmission vehicle. More than likely, he or she will downshift to allow for a possible “go” scenario without a full stop.
As you come to a complete halt, your engine’s revolutions per minute will dramatically decrease. At this point, you will need to engage the clutch to disconnect the transmission from the engine to avoid stalling in the idle state.
With an automatic vehicle, we lack the privilege of manual separation. The labeled ‘automatic’ indicates the vehicle does everything by itself. This is where the torque converter offers its assistance.
A torque converter consists of the following main components: housing, fins, pump, and impeller.
The housing and fins are directly connected to the flywheel, so they are driven at the same speed as the engine.
As the pump spins, it cycles the transmission oil by forcing it to the outside and drawing more in at the centre through a vacuum.
This then injects the transmission oil into the impeller, which will spin and drive the transmission as a stand-alone component without the engine.
How does a torque converter work?
In vehicle torque converter acts as a hydraulic coupling connecting the engine to the transmission.
In simple terms, imagine two electric fans placed facing each other. When you switch on one fan, the air it blows causes the other fan’s blades to rotate.
This is a great way to visualize the basic principle behind a torque converter. However, instead of air, a torque converter uses a transmission fluid to transmit power.
Now, let’s delve deeper into the torque converter and better understand its key components:
- Flywheel (engine’s flex plate): Attached to the engine, the flywheel is the driving force. It’s akin to the first fan that’s switched on, setting everything else into motion.
- Pump (impeller): Fixed to the torque converter housing, the pump is like our blowing fan. When the engine spins the flywheel, the pump also spins, circulating fluid throughout the converter.
- Turbine: The turbine is connected to the vehicle’s transmission input shaft, acting much like the second fan that isn’t powered itself but spins in response to the fluid moved by the pump. This spinning motion is transferred to the gears of the transmission.
- Stator: Located in the center, the stator redirects the transmission fluid returning from the turbine back to the pump. This redirection is crucial for increasing efficiency and torque when the vehicle is accelerating from a stop. At steady speeds, the stator’s job is less critical, but it’s vital for a smooth and efficient takeoff.
- Torque converter housing: This houses all the components and connects to the flywheel, ensuring that the engine’s rotary motion is contained and transferred efficiently.
Torque Converter Location
The torque converter is located between the engine and the automatic transmission. To diagnose it correctly and carry out a visual inspection, you must remove the vehicle’s transmission and 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 always recommend that you remove the torque converter from the transmission to diagnose it properly.
Symptoms of a Bad Torque Converter
Issues with a failing or lousy torque converter are often misinterpreted as transmission problems. As a result, car owners will wind up spending thousands of dollars replacing or rebuilding their transmissions.
They might not know that the issues lie within their torque converter, which is lesser than the transmission itself.
If the torque converter goes bad, the vehicle engine is required to do more jobs to sustain the same engine speed. The engine will require more revolutions to operate per minute, which will reduce fuel economy and fluid pressure.
In the worst scenario, the system will create more heat which could cause issues for other components. Let’s quickly look at signs of a bad torque converter.
#1. Gear shift problems.
If you’re experiencing a soft or delayed gear shift, chances are, you have a lousy torque converter. This is mostly a result of lowered pressure output. Instead of having a nice and crisp transmission shift, you will experience a rough and abnormal gear shift.
The best way to get that crisp and nice gear is to increase the torque converter output pressure by increasing the engine RPM.
#2. Car speed problems.
If you have inconsistent torque converter output pressure, it could result in a sudden increase or decrease of the vehicle speed by the torque converter. At that moment, the throttle will start malfunctioning because there will be varying fluid pressure.
When this happens, It could be dangerous to drive your vehicle, so don’t drive it until you fix it.
You may experience a shudder feeling, but you shouldn’t forget to call your mechanic to inspect the transmission mounts and tighten them if they are loose before inspecting the torque converter.
#3. Shuddering.
If your car vibrates or shakes while driving 30 mph to 45 mph, chances are you have problems with your torque converter. The vibration might seem like when you’re driving on a bumpy road, so you can easily spot it.
The shuddering feeling will not be a consistent thing. It usually happens and goes away suddenly. You should call your mechanic to inspect your transmission once you notice it the first time.
#4. Transmission slippage.
A lousy torque converter will easily showcase Itself because it cannot manage fluid properly. It will either take too much or too little fluid into the transmission, causing gear slippage, resulting in low acceleration.
There will be a decreased fuel economy as well. The transmission fluid might reduce too. You should always check your transmission fluid whenever you notice transmission slippage.
#5. Whining or rattling noise.
Every car has some kind of noise they make. When you drive your car for a long, you should tell when something is wrong by listening to the car noise.
Likewise, when a vehicle torque converter fails, the car will give a bad torque converter noise–a whining or whining sounds like a power steering pump with little or no fluid in it.
The torque converter is built with a clutch mechanism; when the mechanism fails, you’ll notice a whining or rattling noise that might not be heard when the car is in the park.
If the whining noise increases when you engage the transmission gears, it tells you to have torque converter problems.
You might then ask – what causes a torque converter to fail? A torque converter can fail due to many factors.
Torque converter failure can result from excessive friction, which could be caused by a damaged torque converter needle bearing. And, a lousy clutch solenoid and defective seals could be to blame.
#6. Overheating.
some cars are equipped with a transmission temperature indicator that lets the driver know when the vehicle transmission is overheating.
When the vehicle transmission temperature climbs above the optimum operating temperature, you may notice your car will start acting funny, or may even go to fall date and hard shifting or gears not shifting at all.
When two issues are combined, it could be something that is out of place with your torque converter. The apparent meaning of transmission overheating is that the torque converter cannot efficiently transfer power from the engine to the transmission.
#7. Contaminated transmission fluid.
As a hydraulic and fluid coupler, the torque converter won’t work properly without good and quality transmission fluid. Suppose the transmission fluid gets contaminated. Anything that uses the fluid will be affected to an extent.
If you notice your transmission fluid is contaminated along with any of the symptoms above, chances are you have a failing or lousy torque converter.
#8. Fluid leaks.
if you experience fluid leaks dripping from between the transmission and the engine, there are chances that you have damaged torque converter seals. Several factors can negatively affect the torque converter seals and cause them to leak.
When you experience fluid leaks, the torque converter isn’t retaining the right amount of transmission required to transfer power from engine to transmission. This will cause damage to the transmission and the engine in the long haul.
Causes Of A Bad Torque Converter
Torque converters, despite their robust construction, are not immune to wear and tear. Several factors can contribute to their deterioration and eventual failure. Let’s explore some of the common culprits:
#1. High Mileage.
As with any mechanical component, the lifespan of a torque converter is limited. As your vehicle accumulates mileage, the internal components of the torque converter experience wear and tear, leading to potential issues.
#2. Overheating.
Excessive heat is a nemesis of automatic transmissions, including the torque converter. Overheating can be caused by various factors such as towing heavy loads, driving in extreme temperatures, or a malfunctioning cooling system.
The intense heat can damage the delicate seals and components within the torque converter, impairing its functionality.
#3. Contaminated Transmission Fluid.
Transmission fluid plays a vital role in lubricating and cooling the torque converter. If the fluid becomes contaminated with debris or metal shavings, it can wear down the internal components and disrupt the smooth operation of the torque converter.
Regular transmission fluid changes are crucial for maintaining the health of your torque converter.
#4. Defective Needle Bearings.
Needle bearings within the torque converter facilitate smooth rotation and power transfer. Over time, these bearings can wear out or become damaged, leading to noise, vibration, and potential failure of the torque converter.
#5. Worn-Out Clutch Lining.
The clutch lining inside the torque converter is responsible for engaging and disengaging the transmission. Wear and tear on the clutch lining can result in slippage, shuddering, and reduced efficiency.
#6. Defective Torque Converter Solenoid.
The torque converter solenoid controls the flow of transmission fluid to the torque converter clutch. A malfunctioning solenoid can disrupt this process, leading to problems with engagement and disengagement.
How To Diagnose a Bad Torque Converter?
Diagnosing a bad torque converter can be a bit challenging, as its symptoms can overlap with other transmission or engine-related issues. However, here are the steps and methods you can use to diagnose a bad torque converter:
- Check For Warning Lights: Start by checking your vehicle’s dashboard for warning lights, particularly the check engine light. If it’s illuminated, use an OBD-II scanner to retrieve any diagnostic trouble codes (DTCs). Specific transmission-related codes may indicate torque converter issues.
- Fluid Inspection: Begin with a visual inspection of the transmission fluid. The fluid should be a clear or reddish color and should not have a burnt smell. Dark or contaminated fluid can be a sign of a transmission problem, including torque converter issues.
- Transmission Fluid Level: Ensure that the transmission fluid level is within the recommended range, as indicated in your vehicle’s owner’s manual. Low fluid levels can lead to torque converter problems.
- Transmission Fluid Condition: Rub a small amount of the transmission fluid between your fingers. It should feel smooth, with no grittiness or particles. Any debris or contamination in the fluid can suggest torque converter or transmission issues.
- Perform a Stall Test: A stall test can help diagnose torque converter problems. To perform this test, find a safe and open space, such as an empty parking lot. While keeping your foot firmly on the brake, put the vehicle in drive and slowly apply the throttle. The engine should stall or almost stall. If the engine doesn’t stall, it may indicate a slipping torque converter.
- Observe For Shuddering: During normal driving, pay attention to any shuddering or vibrations, especially during acceleration or when the torque converter is supposed to lock up. These symptoms can suggest torque converter issues.
- Listen For Unusual Noises: Be attentive to any unusual noises coming from the transmission area, such as whining, grinding, or squealing. These noises can be associated with a failing torque converter.
- Check For Delayed Engagement: If you experience a noticeable delay when shifting into gear, especially from “Park” to “Drive” or “Reverse,” it could be indicative of torque converter problems.
- Perform a Road Test: Take your vehicle for a road test and pay attention to its performance. Note any slipping gears, poor acceleration, or an inability to maintain highway speeds. These issues can point to torque converter trouble.
- Consult a Professional: If you’re unsure about your diagnosis or if any of the above tests suggest torque converter problems, it’s advisable to seek the expertise of a qualified mechanic or transmission specialist. They can perform more advanced diagnostics using specialized tools and equipment, such as a pressure test, to confirm the torque converter’s condition.
Remember that diagnosing torque converter issues can sometimes be tricky, and the symptoms may vary depending on the severity of the problem.
Timely diagnosis and repair are crucial to prevent further damage to your transmission and ensure your vehicle’s safe and efficient operation.
How to fix torque converter problems
Fixing a lousy torque converter problem requires dropping down your entire transmission and replacing or rebuilding the torque converter. However, there are tried and tested quick fixes that you can utilize to fix transmission problems.
What you should do to fix shuddering and slipping?
The first thing you want to do when you notice your transmission is shuddering and slipping is to check your transmission fluid level.
You probably won’t know if the slipping or shuddering has to do with your torque until you check your fluid level. Kindly note that shuddering and slipping symptoms usually come up when you have extremely low or wrong transmission fluid type.
What you should do to fix overheating and fluid leaks?
low transmission fluid level is usually caused by fluid leaks, which could result in overheating.
Aside from overheating, low fluid can also cause shuddering and slipping. To fix this problem, you have to find out why the fluid is leaking (usually a damaged seal) and replace it.
What you should do when you have a contaminated fluid?
If you find out you have grits and grime in your transmission fluid, it indicates a more significant issue in the transmission or torque converter, and you should never ignore it.
This shows things are going out of place, and you should take the below step or contact your mechanic.
Generally, the below steps explain what you should do yourself once you notice things are out of place.
You know that the torque converter is a complex device, and when it fails, you have to remove the torque converter, drain the fluid and rebuild or replace it with a new one.
This trick will help you fix your torque converter problems in less than 10 minutes without having to remove the torque converter.
Things Needed
- Floor or hydraulic jack
- Jack stands
- Wheel blocks
- Funnel
- Socket wrench
- Legend instant shudder fix
- Transmission fluid
- Oil Catch pan
- Mechanic lay-board
- Ratchet handles
Step 1. Pack the park and lift it
Park the vehicle on hard and level ground. Then, block off the wheels and lift the car so you can quickly go under the vehicle.
Remember to support the car with Jack stands. Car Jacks alone are never enough to support a vehicle. Grab your mechanic layboard and slide it under the car.
Step 2. Drain the transmission fluid
Slide under the vehicle and unbolt the transmission sump to drain the fluid. Ensure you position the waste oil catch pan directly under the transmission so you won’t mess up the garage floor.
After the drain, fill the fluid in a container and dispose of it later. Put the sump back in place and snug it with your hand. Take the right tool you used earlier and torque the sump.
Step 3. Fill in the new transmission with the recommended fluid
Get the recommended fluid for your vehicle and fill the transmission until it gets to the standard gauge.
The recommended transmission fluid for vehicles is usually written on the transmission dipstick. If you can’t find it on the transmission dipstick, you may visit your owner’s booklet or manufacturer’s website.
Step 4. Lower the Jack and start the engine
Now, you would want to remove the Jack stands and lower the vehicle. Start the engine and re-gauge the transmission fluid. Add more fluid if need be. Once the fluid is gauged, you then move to the next step.
Step 5. Add legend instant shudder fix to the transmission fluid
Instant shudder fix is a perfect product specifically made to fix torque converter problems. The product is usually thick and a bit difficult to pour into the transmission. To make things a lot easier, boil a quart of hot water and power it in a small bowl.
Then, put the instant shudder fix in the bowl and allow it to stay for 5-10 minutes. Once the product dissolves to a liquid form, locate your vehicle’s transmission dipstick and pour the instant shudder fix into the transmission fluid. Put everything back in place, and test drive your vehicle for 10-15 minutes.
What Are the Benefits of a Torque Converter?
One of the main benefits of a torque converter is that it can transmit power even when the input and output shafts are not synchronized.
This makes it ideal for use in automotive applications, where the engine speed may vary widely while the wheels must rotate at a relatively constant speed.
Another benefit of a torque converter is that it can act as a fluid coupling, allowing the engine to idle without stalling the transmission. This is possible because the turbine will continue to rotate even when the input shaft is not turning.
Finally, a torque converter can provide a mechanical advantage, which means that it can multiply the torque generated by the engine. This can be useful in applications where a high level of torque is required, such as towing or hauling heavy loads.
What Are the Cons of a Torque Converter?
While torque converters have many advantages, there are also some disadvantages to using this type of fluid coupling.
One of the main drawbacks is that they are typically less efficient than other types of fluid couplings. This means that they can cause the engine to work harder and use more fuel.
Another disadvantage of torque converters is that they add weight and bulk to the transmission. This can make the transmission less responsive and can cause it to overheat more easily.
Finally, torque converters can be damaged by debris or dirt in the fluid, so they must be regularly serviced and flushed to prevent damage.
Torque Converter vs Other Transmission Issues
It’s easy to confuse torque converter problems with transmission issues, as they often share similar symptoms. Here are some clues to help tell them apart:
Torque Converter Problems:
- Symptoms normally occur at specific speeds or RPMs
- Shuddering is more noticeable during light acceleration
- Noises are typically most noticeable when idling or in neutral
- Issues may come and go, or worsen gradually over time
Transmission Problems:
- Gear slipping or grinding occurs across all speeds
- You might experience complete loss of certain gears
- Noises are usually louder when shifting between gears
- Check Engine light is more likely to come on
One key difference is that torque converter issues often appear intermittently at first, while transmission problems tend to be more consistent.
Also, torque converter problems usually start subtly and worsen over time, whereas transmission issues can develop suddenly, although not always.
But it’s also important to note that a torque converter problem that’s ignored for too long can actually lead to transmission damage. Then the repair costs go up even more.
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. 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. 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, let a mechanic test drive your car and see if he hears any noise or can feel slipping.
Torque Converter Replacement Cost
The average torque converter replacement cost is between $300 and $2500, depending on the car model and labor costs.
A new replacement torque converter costs between $100 and $400. The labor cost to replace the torque converter is between $200 and $2000.
The transmission often must be removed to replace or inspect the torque converter for any problems.
Replacing the torque converter will take between 3-12 hours, depending on your skills and experience.
How to prevent a torque converter failure?
Treating your car right can save you a lot of hassle and unplanned expenses. Here are some steps you can take to prevent torque converter problems:
- Use the right transmission fluid: Using the wrong type of fluid can lead to torque converter and transmission problems.
- Avoid overheating: Ensure your vehicle’s cooling system is in good condition and avoid heavy towing or driving in extreme conditions that could cause excessive heat buildup.
- Check transmission fluid levels: Low fluid levels can lead to inadequate lubrication and low hydraulic pressure, which leads to slower engagement when shifting gears.
- Pay attention to your driving habits: Avoid abrupt starts, aggressive acceleration, and sudden stops. These behaviors can put extra stress on the torque converter and transmission.
- Use parking brake: When parking, engage the parking brake before shifting into “P.” This reduces the strain on the parking pawl within the transmission, which indirectly affects the torque converter.
- Perform regular checks: Using scanning or diagnostics tools like OBDeleven NextGen is a great way to keep track of your vehicle’s performance and health. It can help you identify any issues with your transmission system by showing you the transmission fault codes.
Additionally, you can view live data parameters like torque converter hydraulic pressure, transmission fluid temperature, selected gear, and torque converter clutch slipping, which can help you stay on top of your car’s maintenance needs.
FAQs.
Q: What does a bad torque converter sound like?
It is known that every vehicle makes a sound. Knowing your vehicle’s sound will save you a lot and tell you when something is wrong.
If the torque converter starts failing or it’s completely gone, it will give some odd noise like whining or rattling noise. The sound will come on and suddenly disappear within seconds.
Q: Will a bad torque converter throw a code?
The query, will a bad torque converter throw a code – has been a concern to an average car owner. This question has been asked zillion times in automotive forums.
A lousy transmission solenoid will register a diagnostic trouble code (DTC) which will trigger the check engine light to pop up.
Q: Will a bad torque converter make a knocking sound?
A bad TC will make an odd sound like a piston slap or a knock con-rod if you have loose torque converter bolts. But it’s just the torque converter hitting the flex plate. Fixing this sound will only require tightening the bolts as long as it hasn’t affected anything yet.
Q: Can a bad torque converter damage transmission?
Absolutely yes. A lousy TC can cause transmission fluid degradation, overheating, and friction damage. The more you ignore the torque converter problems, the more it causes damage to the transmission.
Final word
Torque converter problems can be averted once you know the symptoms to watch out for. Once you notice the symptoms, it is important to fix them.
You’ve now known what causes a torque converter to fail, the symptoms of a bad torque converter, and an easy-fix method to fix a failing or lousy torque converter.
If you’re not confident enough to carry out the repair process yourself, call your mechanic to handle the repair.
The repair or replacement cost of the torque converter is inexpensive compared to the damages it could cause to the transmission if ignored for a long. Therefore, it is important to diagnose and fix torque converter problems in the earlier step.