Torque Converter Problems: Symptoms & Replacement Cost

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.

Need a replacement transmission? Get an estimate for replacement transmissions and local installation. Look up your transmission model by vehicle make and model.

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:

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.

Torque Converter Between Engine Driveshaft

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.

Torque Converter Separated

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:

  1. Start your car and let it run for a couple minutes
  2. Press the gas down lightly several times
  3. Push the brake and shift the car into drive
  4. Slowly shift through each gear
  5. 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.

RepairCost 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.

Need a replacement transmission? Get an estimate for replacement transmissions and local installation. Look up your transmission model by vehicle make and model.

What Transmission Do I Have?

Over to You

What problem do you think your torque converter has? What symptoms is your car experiencing?

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Brandi Mcnair
2 months ago

Check engine light came on. Code 0p740. At first it jerked slightly putting into drive. No shift problems. Rpm’s up a bit. Gas mileage slightly less. Whining noise. Drove a few times not over 4 miles or 40 mph. Today…clunck noise from park to drive. Reverse same. Just started shutter. Will replacement of torque converter clutch solenoid fix?

Larry
2 months ago

Will go in neutral and reverse not go into drive transmission fluid on ground.

Josh
3 months ago

Tahoe will drive, reverse on cold start but then will not accelerate and stop moving after a few minutes.

Mel emery
3 months ago

Shifting hard going up hill with cruse control on then starting smoking for a few minuts

Mike
3 months ago

Trans slams.out of drive starting out at Green Light has happened three times in two weeks every time has happened has been aftrr long high speed (freeway) driving but after slippage it seems to be normal and ok , no problems prior to this with almost 200,000

Krystle Hinson
3 months ago

I have a ford van and was told it there converter but will not move out it’s spot and is not driveable is it the transmission?

Robert J Menzock
3 months ago

2004 Chrysler 300 limited does not move when shifted into any gear. Replaced solenoid pack, speed sensors, friction disks and steels. Proper level of ATF+ fluid.

Bev McAdow
4 months ago

PO744(2/3) PENDING A/T TORQUE CONVERTER CLUTCH SOLENOID VALVE FUNCTION

My car was on I90 at 70 miles per hour and then slowed to 50 m/h.

Approximately 400 miles prior to this there was a terrible loud banging noise under the hood, which I thought it sounded like something got caught around the axel. Saw nothing so I keep going.

Rlynn
4 months ago

The car will idle normally until it’s put into gear (D or R), then it shudders and dies. It’s a 2011 Hyundai Sonata

Last edited 4 months ago by Rlynn
Mary McClure
4 months ago

Need torque converter for mini Mayfair 998 automatic

charlie
4 months ago

move from reverse to drive – lock in neutral

Kesha
4 months ago

Once my abs traction light comes on my car won’t accelerate over 60 speed and and jerks . Only happens when my traction light appears. I ran a engine light check and something about a torque came up in the codes

anthony burton
4 months ago

Well my tourque converter was just about to go out so I changed it. My question is this I have a 2001 subaru outback with the 2.5l the T C that was in the car had a stamp on it that said 90 the one I put in it had a stamp that said 150 I started it for about 5 seconds and it made a high pitch squeal I imeaditly turned it off this is where I am

Adrian Cantu
5 months ago

So I don’t get no acceleration when I put my 2000 Honda Accord LX in reverse or drive D4 or any gear in that Matter. It’s not showing me on my dash any mileages it stayed at 0 and won’t let me go any we’re

Josh
3 months ago
Reply to  Adrian Cantu

Tahoe will drive, reverse etc on a cold start but then after a few minutes it will no longer accelerate and will no longer move.

Ray
5 months ago

Light is on making a winding sound on transmission Kia soul

KEITH B LEWIS
5 months ago

CODE 8410 dodge ram 1500 4×4 4.7 engine

Carl
5 months ago

Not to peppy….when accelerating

Jon
5 months ago

2009 Pontiac g6 3.6L…. While driving down level road is fine, once you start going up any type of incline, it starts to feel like its slipping out of gear.. untill you push accelerator harder and drop down a gear, with higher rpm

Edwin
5 months ago

Water in transmission from a bad transmission cooler

George Shell
5 months ago

2000 nissan xterra RWD 3.3L

George Shell
5 months ago

Tranny has been slipping a little between gears in lower speeds then all of a sudden tranny I think went into limp mode I could go around 30 mph and get no response from pedal after that now when I go to start it starts fine until I put it into any gear then it bogs and dies on me

375
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