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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Leave a Comment

K

94 Jeep Wrangler when I come to a stop it wants to keep going. If I leave my foot on the brake it will die but if I shift it to neutral it will stay running. Need help

Mark Ball

08 ford Escape tourqe converter has somehow scrubbed against the bellhousing and create a lip on the torque converter where front seal will not come off of the torque converter does this mean I need a new torque converter

Christopher Nash

Just bought 98 dodge ram 1500 with 5.9L has 153,000 miles. Less then 20,000 on rebuilt transmission. They added larger pan. It sometimes seems like it shifts twice, sometimes have to press gas pedal more then should to get it to accelerate and I’m averaging 10.5 miles to gallon. Suppose to be 11 city 16 hwy and I do about 50/50. Is this a torque converter issue or something else?

Keith Shealy

Want go in any gear after I replaced the front seal the engine turned over then locked up so I took the transmission back down an put the torque converter on probably put up transmission now no movement in any gear

Keith Shealy

1991 f350 7.5 e40d transmission by the way I really need help

Angie Baldridge

I have a 2007 ford crown Vic police interceptor and it will not change into 3rd gear

Johnny

Torque converter clutch circuit electrical system 2003 mercury marauder code po743

SGMworks@optonline.net

Engine shuts down on breaking
2015 ram promaster 2500
No check engine or other indicator lights would appear.
Engine would not stall on very light breaking to stop.
Regular breaking would stall, sometimes launch truck slightly forward with RPMs fluctuating .
At this point by shifting into neutral engine would not stall.
Been apx-four weeks at the dealership service department now. They changed out the brake booster that didn’t work. Now they have an A-technician on this saying torque converter? The FCA is also involved”any answers for this would be appreciated..

Bill R.

04 trailblazer 4l60e. Had trans rebuilt about a month ago including(supposedly)new tc. Yesterday it started slipping and neutralizing. Turn off restart, it works for a minute then will neutralize again. Turn off restart same thing over and over. Does good when cold messes up when warm up

dan

teaspoon of fluid leakin out of the dustshield daily

Kirstin

I have an 05 Ford F-150 with a 4R75W tranny. All of a sudden one day it simply would not go. I put it into drive and nothing happened when I stepped on the gas except the rpms would rev up. The codes I have right now are p0731, p0720, p0732, and p2106. Does anyone know how to diagnose these?

Robert Sanderson

I just got a transmission rebuilt a few weeks later my engine light came on and i had a reading saying that my transmission was slipping i took it back to the shop were i had my trans rebuilt he straight told me it was my torque convertor so im thinking that should of been included in rebuilding my transmission in the first place im i correct.

Doughgurl2

Yes, i was thinking the same thing because it happened to me on my 05 acura tl

Michael Overstreet

Replaced tranny in my 2003 avalanche it ran 2 days and then lost all gears at once

Leah

I have a 05 chevy tahoe. Its making a terrible grinding noise. When I put it in reverse with my foot still on brake its grinding so loud. When I put it in drive it doesnt make that noise until i take my foot off brake. I had transfer case replaced and the noise is still there. It seems to shift fine. But the noise is constant so I cant drive it. ANY IDEAS?

Joey

My 99 Dodge 1500, has a new problem. I start it in the morning and all is ok. As soon as I put it in “Drive”, I hear a clicking noise from the transmission. I thought it was the flex plate, but I looked closer and found no cracks or warps that would cause that kind of noise.

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