Torque converter problems are sometimes misinterpreted as symptoms of a failing transmission. Unfortunately, this can lead people to think that they need to spend thousands of dollars to rebuild or replace their automatic transmission when the cost to replace a malfunctioning torque converter is considerably cheaper.
What Transmission Do I Have?
A local auto repair shop will be able to determine whether or not the problem lies in the transmission itself or the torque converter. Finding a reputable shop is very important because as we have mentioned, the symptoms can be very similar and a transmission replacement is considerably more expensive.
In This Guide:
- What Does a Torque Converter Do?
- 6 Signs of Torque Converter Problems
- How to Diagnose the Problem
- Causes of Torque Converter Issues
- Replacement Cost
However, diagnosing the cause of a transmission issue isn’t easy. In many cases, the torque converter will not actually be the source of the problem (you might just have a fluid leak!). The purpose of this guide is to simply help you narrow down the possibilities and educate yourself before you get your transmission checked out.
What Does a Torque Converter Do?
In a nutshell, a torque converter is a fluid coupling that transfers torque from the engine to the transmission. It is mounted between the engine and transmission, bolted directly to a ‘flex plate’ which is spun by the crankshaft.
Internal combustion engines create power by burning fuel that forces the pistons to turn the crankshaft located at the bottom of the engine. This rotational force is transferred to the transmission by the fluid pressure inside the torque converter.
Inside of the torque converter cover lives a series of propeller-like blades called the pump. This assembly spins in unison with the engine crankshaft, forcing transmission fluid onto another blade assembly called the impeller. This second set of blades is connected to the transmission input shaft. The amount of hydraulic pressure that it creates inside the transmission dictates the gear and ultimately, the speed of the vehicle.
The impeller’s speed is regulated by the engine side of this hydrodynamic circuit (ie. speed of the pump blades). When the vehicle is stationary, or the driver applies the brakes, the impeller will slow considerably, while the pump continues to spin. This allows the torque converter to act like the clutch in a manual transmission – it allows the engine to continue running while the vehicle is at a complete stop.
Once the transmission fluid has been hurled onto the impeller blades, it has to return to the pump in order to keep the cycle going. Since the fluid is now flowing in a different direction than the pump, it has to be reversed to avoid slowing down (and stalling) the engine.
To do this, a third finned wheel called the stator is located between the two turbines on the transmission pump shaft. Its blades are precisely angled so that when the transmission fluid hits them, it reverses direction and gets channeled back to the pump. When the vehicle stops, its built-in one-way clutch causes it to stop spinning, breaking the hydrodynamic circuit.
Once the vehicle starts to accelerate from a stop, the stator is once again free to spin. In the split second that the transmission fluid hits the back of the now-released stator, it starts to spin the transmission pump, and briefly multiplies the torque coming from the engine side of the circuit. This causes the transmission pump to force more fluid in the transmission, resulting in movement.
Once the vehicle is in motion, the stator’s one-way clutch allows it to start spinning in the same direction as the other turbines, reversing the fluid flow and completing the hydrodynamic circuit.
After all of the transmission gears have been shifted through and the vehicle has reached cruising speed, the lockup clutch engages, connecting the front cover of the torque converter (aka the pump) to the impeller. This causes all of the turbines to work together in a direct drive/overdrive scenario.
6 Signs of Torque Converter Problems
It isn’t easy to isolate and diagnose a torque converter issue without taking the transmission/drivetrain apart, but there are several symptoms to look for. A few of the signs of a malfunctioning torque converter include: shuddering, contaminated fluid, gears change at high RPMs and strange sounds such as clicking or whirring.
Slipping
Since a torque converter is responsible for translating engine torque into the hydraulic pressure needed to shift gears inside the transmission, a damaged fin or bearing can cause the transmission to delay a shift, or slip out of gear.
Slipping can also be caused by there being not enough or too much fluid in the transmission. You may also experience a loss of acceleration and a noticeable reduction in your car’s fuel economy.
Be sure to check your fluid levels before taking your car to a shop.
Overheating
If the temperature gauge indicates that your car is overheating, it could be a sign that there has been a drop in fluid pressure and there is a problem with your torque converter. If a converter is overheating, it won’t be able to transfer power from the engine to the transmission. This results in poor throttle response, and excessive wear and tear on the internal workings of the transmission.
Low fluid levels or a malfunctioning solenoid can also cause a transmission to overheat.
Shuddering
If the lockup clutch inside the torque converter is starting to malfunction, you may experience shuddering at around 30-45 mph. The sensation is very noticeable and typically feels like you’re driving over a rough road with many small bumps. As the converter switches over to direct drive, a worn lockup clutch can make the transition difficult, resulting in this sensation. The feeling may start and stop abruptly and may not last long, but if you’ve experienced it several times, it’s time to get your transmission checked.
Contaminated Transmission Fluid
A torque converter is filled with automatic transmission fluid (ATF). If the fluid is contaminated, it can do damage the parts inside. This can result in worn bearings on the stator, or damaged fins on one of the turbines.
If you notice a significant amount of black sludge/grime/debris in the fluid it could mean that the converter or transmission itself is damaged. In this case, change the fluid and drive around for a while before checking the fluid again. If the problem persists, get your car checked by a professional.
Higher Stall Speed/Gear Engagement RPM
The ‘stall speed’ is the point at which the engine RPMs are high enough for the torque converter to transfer power from the engine to the transmission. In other words, it is the RPM at which the converter will stop the engine speed from increasing if transmission output is prohibited.
If the torque converter is broken, it won’t be able to transfer the engine’s rotational force into hydraulic pressure correctly. This will result in the transmission taking longer to engage the engine, causing the stall speed to increase. Here is how to do a stall speed test. You’ll have to find out what your vehicles stall speed is beforehand (typically 2000 to 2500 RPM).
Strange/Unusual Sounds
It’s not uncommon for the torque converter to emit strange noises as it begins to fail. Some of the sounds you might hear include a ‘whirring’ sound coming from bad bearings, or ‘clinking’ sound coming from a broken turbine fin.
How to Diagnose the Problem
Here is how you can try diagnose the problem yourself. At each step, listen carefully for unusual slipping, shuddering, lurching forward or strange noises:
- Start your car and let it run for a couple minutes
- Press the gas down lightly several times
- Push the brake and shift the car into drive
- Slowly shift through each gear
- Drive around the block, listening carefully every time you accelerate
Do Not Drive With a Broken Converter
Important to note – a converter can slowly fail over the course of several weeks or even months before it completely breaks down. Driving a vehicle with one that is damaged can be risky as it can completely disintegrate when it breaks down – adding metal debris into the transmission fluid. The contaminated transmission fluid can then make its way into the transmission and cause significant damage or even complete failure, turning what could have been a simple converter replacement into an expensive transmission repair or replacement. To prevent this, pull off the road when it is safe to do so and shut off the engine.
Common Causes of Torque Converter Problems
There are a few reasons why problems can occur. Don’t assume what the problem is until you have your transmission looked at, but here are some general ideas of what it could be.
Bad Torque Converter Needle Bearings
The impeller, turbine and stator use needle bearings in order to turn freely. The bearings separate these rotating components from the converter housing. If these bearings are damaged, you’ll notice reduced power, strange noises and bits of metal in the transmission fluid due to metal on metal contact/grinding.
Damaged Torque Converter Seals
If you notice a transmission fluid leak coming from the bell housing, then you might have a damaged torque converter seal. If your torque converter can’t hold the proper amount of ATF, then it won’t be able to transfer power from the engine to the transmission effectively. This will result in overheating, shifting problems, strange noises, higher stall speeds, and slipping between the gears. The bad seal will need to be found and replaced.
Worn Torque Converter Clutch
Automatic transmissions have a number of clutches located throughout the assembly. A torque converter clutch is responsible for locking the engine and transmission into direct drive.
If the torque converter has been burned by overheating, become jammed/locked up due to distortion or contaminants in the transmission fluid have damaged the friction material on it, then your car may stay in gear even though you come to a stop. The converter can also shake and not lock itself into direct drive if the friction material on the clutch plate has worn away.
Faulty Torque Converter Clutch Solenoid
A torque converter clutch solenoid regulates the amount of transmission fluid that the converter’s lockup clutch receives. If this electronic device can’t accurately meter the fluid pressure, then the lockup clutch will not work properly as a result of too much or too little fluid supply. This can result in loss of the direct drive function, poor gas mileage and engine stalling.
Torque Converter Replacement Cost
If you’ve noticed one or more of the above symptoms, then it’s possible that your torque converter is malfunctioning. The cost of getting it repaired can be higher than simply replacing it, so be sure to have a mechanic/technician take a look.
| Repair | Cost Range |
|---|---|
| DIY | $150 to $500 |
| Transmission Shop | $600 to $1000 |
If you plan to do the work yourself, then you’ll be looking at a repair cost between $150 and $500.
Repair shops will charge between $600 and $1000 to replace a torque converter.
The torque converter itself is relatively inexpensive (between $150 and $350, depending on the vehicle), but 5-10 hours of labor is involved since the transmission must be removed in order to replace the torque converter.
The fluid should also be flushed/changed at the same time, which may or may not be included in the price a shop gives you.
What Transmission Do I Have?
Over to You
What problem do you think your torque converter has? What symptoms is your car experiencing?
2004 yukon denali torque converter seal replace how much will it cost
Torque converter seal replacement
1999 F150 4×4, 4r70w. Start motor, some vibration. Makes a whinning/whirring noise only in reverse or a forward gear. I have transfer case in low range, takes about 2500 rpm to move vehicle. Trans fluid does not smell burnt.
It has, in the past, killed the motor when coming to a stop, and has downshifted hard when coming to a stop.
My 2011 chevy impala doesn’t go into drive
2015 dodge charger is shifting slowly and not sending any obd2 codes
2015 dodge caravan : I was getting a circuit code (Po740) but my car drove perfectly normal. Then out of the blue the code went away and I noticed the tachometer was locking at highway speeds for example on the highway while driving constantly at 60 mph on cruise control the tach Wokld remain constant at 1500 rpm even when going up on inclines of highway overpasses. But after 2 weeks the p0740 code came back on telling me that the faulty circuit code returned but the caravan still drives perfectly normal in both the city and highway. I’m thinking the torque is okay and it’s just either the solenoid or bad wiring/connectors?
hesitates a couple of times at 45 mph but if I accelerate faster when I first get in it doesn’t do it.
When the transmission is cold it shifts fine but when it heats up it startea shifting vary hard an my 3rd gear an overndrives start alippin bad
It’s a GM th350 by the way
Torque converter is making an internal rattling sound in drive or reverse when stopped. Also the entire converter is wet. The transmission is still operating normally though. It isn’t loose bolts or a cracked flexplate. That’s what everyone keeps suggesting, but the sound is coming from within the torque converter
99 Tahoe automatic transmission code p1870. Only go 40mph reverse is ok. Not slipping wont change into 2 or any other gear. Changed fluid, filter and 2 scenoids.
6L80 transmission Silverado lost forward gears when driving check engine p0796 light still had reverse had towed home started it up had forwards so shut off changed fluid and filter had sludge around magnet and could see metal shavings put pan back on and took for test drive seemed good till got to operating temp reved higher and no 5 or 6 speed what to do next trying to keep cost minimal
It was working fine I stop got gas started it up an for
1ward or reverse did not have nothing
Transmission shudders around 45 to 55 mph
2004 Chrysler Sebring Limited with 3.0 v6. Was working fine then without warning it stopped pulling and dumped all the transmission fluid on the ground. Refilled with fluid, drove approximately 2 miles and done the same thing. Pulled car 5 miles home in neutral and now it doesn’t go in gear and is making a little clicking noise
Don’t wanna shift into drive or reverse from stopped position. Will SLIP into drive if driving down the road. Shifts into 1st or 2nd hard from stopped position. If I kick it down to pass a car it just revs up real high instead of providing more power. No leaks. Good fluid. Just started all the sudden.
Transmission sometimes engages into gear then sometimes it won’t do anything at all I changed the fluid and filter and now makes a whining noise before it goes into gear
So i replaced my CV Axle on my 2001 infiniti I30. The same engine as the Nissan Maxima. And i did not get a new inner drive axle seal. Long story short i finished the job and my old seal ended up getting slightly torn while my car was on blocks waiting for the bearings to get pressed. I also did a drain and fill when i did the axle. The fluid was fairly old but i never had shifting problems nor did it smell burnt. Ive been driving until i noticed my seal was leaking severely. So i regularly been checking my tranny fluid level to keep it full and ive still been driving on it as i procrastinate fixing it. One day i went to start my car and it wont go in reverse. When i put it in reverse it goes forwRd if i hit the gas. In neutral i move forward. But when i turn the car off and turn my key on engine off so i can shift into reverse it lets me move backwards. My check engine popped up as torque converter solenoid circuit intermittent. And my car is in limp mode. I do all my own work and am learning as i go as you can tell. So much cheaper. So what the hell do i do. Obviously fix the seal. I read when i put my cv axle back in i need to pack it with grease? Is that true? And did i damage my tranny or TC solenoid when i drain and filled the old fluid? I really need this car to last just a little longer. I need some serious education regarding my situation please.
2012 Buick Enclave throws code 0741. Shudders at low RPMs in gear especially at highway speeds. Seems to not know what gear to go in
My 2014 Dodge Charger has an egine light on for the torque convertor solenoid circuit, and its shuddering from about 35-55mph. I read somewhere else that it could just be low on transmission fluid? Should I check fluid first or does that even have anything to do with the shuddering?
2006 trailblazer 4.2L 4l60E lost 3rd gear pulled transmission found checkball stuck in separator plate and third gear clutches were severely burnt but not worn and there was a lot of metal in the pan so where did the metal come from and why was 3rd gear clutches severely burnt but fourth gear clutches were fine? Don’t know what to look for other than replacing the separator plate place in the clutches and steals that was burnt and hoping that there was no other problem except for where the metal came from
I have this same issue currently and I think it’s the torque converter but not sure
My 07 equinox starts perfectly fine. When putting it in drive, reverse, I, and L; the vehicle is not wanting to budge. The rpms go up but no sign of movement whatsoever. Transmission fluid has been drained and replaced properly and still having the same issue. Driving home one day going roughly 65 mph the vehicle would vibrate and shift to wother the left or right so often. That was before it was undrivable. I’ve only been able to drive the vehicle once since all this had happened. It started the day I bought it and brought I home. Hasnt been and wont move since. Im thinking it’s either the transmission its self or the torque or catalytic convertor. Any advice?
Thanks!
Give it a push my Nissan did this and all we did was push it till about 10 miles per hour and slammed it in drive and then it just started working