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?
my Hyundai fluidic verna car own moves on reverse and reverse act like another neutral mode
Well ok .. took the ’08 RAM 3500 6.7 diesel automatic with the 68RFE transmission down to the dealership and, following the maintenance schedule, had the trans, transfer case, front and rear dif fluids changed out.
The invoice shows they used the same trans fluid as my manual says.
However, despite showing the guy my manual’s recommendations, the front and rear diff have been filled with something else.
Manual says rear and frond diff need GL-5 75W90 Synthetic.
Invoice says they used a 75W85 Synthetic ( half the price ).
Contacted the dealership and they claim the fluid list is generated by their Dodge computer system off my VIN and that the fluid spec’d in my manual has been ‘superseded’ by the fluid they used and that I abosolutely do have the correct lube in my American limited slip diff.
Anybody else had this happen? Comments?
I worked at an auto parts as a delivery driver and found out through mechanics and articles at work that the fluids, greases, etc. have different chemical makups now than 10 years ago. That is why they now recommend longer intervals between oil changes. Hope this helps
I’ve been told if it ain’t broke…don’t fix it.
I’ve also heard that transmission flushes can make a transmission start slipping because it breaks down the protection film built up inside it from the transmission fluid.
If the color of your fluid looks red, I’d leave it alone. Make sure the vehicle is running and is in park or neutral to check the fluid level.
I have a low mileage RAM 3500 6.7 diesel automatic with the 68RFE transmission. (Truck has 62,000 miles). I’ve hauled a heavy truck camper pretty much 100 percent of those miles, and I am calling that extreme service, and the manual says it is time for transmission fluid changeout.
The RAM dealerships tell me that the service they provide will NOT remove the transmission fluid from the torque converter or the transmission cooler lines, but just the fluid in the transmission itself. That would leave close to half the old fluid still circulating in the fluid loop.
On the other hand, I am far from expert in these matters and I wonder if a transmission flush is the right thing for this transmission?
I just watched this video the other day because I am debating getting a transmission flush myself. I work at a reputable auto shop as a service writer. I am going to change the fluid, but not flush the transmission. I hope this video helps you, whatever you decide to do. https://youtu.be/or9u8DQ4fVU
all you have to do is remove the pressure line from the radiator, if there is a line on top and on bottom the bottom is the pressure side and top is return to trans, or if they are both along bottom then passenger side is pressure, so, remove pressure line, hook hose up to line to drain into a pan, have someone help if possible, start the car and let it pump out the fluid until it starts bubbling, shut it off, remove pan, clean and replace filter and put pan back on, leave pressure line unhooked and hose left on, add fluid back into the transmission 2 quarts at a time until its around the full mark, if alittle high, no problem, start it up again and let it pump out the fluid until bubbles, shut it off, if fluid is still dark then do it again until it comes out looking new, once it comes out looking new then hook the line back up, fill transmission to the full mark, start car and let run for 2 or 3 mins to warm up, check fluid again while idle in park, if low, add to full mark, put transmission in lowest gear and drive a few feet and do that in every gear, check fluid level again, add if needed, drive around for a few blocks then check level again once its operating temp, add as needed, you now have a flushed transmission and new filter with new fluid lol enjoy
Driving along about 35-40mp35-40mph.like a.pressure release and then no gears coast to a stop. With engine still running I run through the gears no action, no gears, simply nothing. Check oil level and it was way over full. I’ve already draped the tranny. They told me I had blown the pump. I was going to change it but then I read it might be the converter. So now I bought a tranny and converter. Should I put my old stuff back and drain the excess fluid and it will work?
2014 Ford Escape with 90K miles , fault light came on, haven’t been experiencing any noticeable issues while driving. Parked it and only drove it to dealer. They gave a price of under 3,000.00 so I can expect it being a hunk of money, right? Having it towed to a transmission place instead. Ford knows they got issues with these transmissions!
Check engine light codes torque converter in 1999 Deville with 153,000. No noises, no hesitation, smooth shifting and smooth stops. What’s up?
Sounds exactly like what happened to my 04 F150 with the 4r75e trans. If you find out what caused it, please post so I can try it. If I find a solution in the meantime, I’ll do the same.
Thanks
2006 ford freestar, approx. 260,000 miles. Changed fluid & filter. 5 days later, about 1,000 miles, tranny just quit pulling in any gear, including reverse. No noise! Checked fluid level; full, color; bright red.When engine is speeded up to 3,000 rpms drive wheels try to turn slightly, maybe 1″. Torque converter? Been told by 2 transmission shops these tranny torques are notorious for going bad. They wanted $1,000 & $1500 respectively plus parts to get my van back on the road. I know I can get a rebuilt torque & rear main seal for apprx. $150. What should I do? Barely have enough money to get by on now.
Just had same thing happen to my 2006 Taurus. As soon as I did a Google search, I found that 2005-2006 Ford Taurus and Van trannys have issues w/ the Torque Converter splines stripping out. No damage to remainder of transmission.
Search under Taurus if you can’t easily find a Van link.
I’m looking @ approx $800 in labor and 150 or so on parts. Beat the $2300 or a new transmission (inc install)
My car is transmission is bad and slip 2004 Honda Accord coupe V6
i have a volkswagen toureg 3.0 litre which is on 56 plate and automatic. i have a problen with the transmission as the car is stationary and wont move whatever gear it is in. i was out in it and this suddenly happened no overheating no sign of leak and no smell of burning. The garage have been told the part is G195 AND G182 WE DONT KNOW WHAT THIS IS CAN ANYONE HELP PLEASE
My 1996 Honda slips in 2nd and idle high. Have to let up off gas for it to kick in seem to be getting worse. Is it the transmission or torque converter. I have 313000 highway miles everything else on the car works good.
It really helps me a lot to understand about torque converter working.
can you tell its advantages and disadvantages?
My dealer told me that, after diagnostics were done, that my torque converter was “disintegrating’ and sending metal shards through the transmission– thus the need for a new $2500 transmission. Can they diagnose this without taking the transmission apart and actually looking inside. I did drive after getting a converter solonoid fail diagnosis.
Good day,
I am having the same is and have been giving the same diagnoses. How long did you drive afterwards?
2005 Ford F-150 has reverse, but no forward , no grinding noises . Dropped pan no shavings . No burnt smell , I’m wondering if it’s possible if a silinoid or something that’s simply electrical that may be causing this problem.. thank you for any advise in this matter
Jumping in out over drive
Hi I’m have tran or something else going wrong with my 99 dodge ram 2500 4×4 I was driving at like 65 mhp and for some reason truck act like is went into neutral no matter what I do with tcase or transmission it dnt move there is a slight winding coming from front of the trany by convertor please help
No reverse. All gears including neutral are forward.
My trans is making a noise best described as a scraping or rattling sound. It goes completely away when I put it in gear. Forward or reverse. It is not present as long as there is a load on it.
Mine is the same. Auto Transmission. Rattle at idle or reducing rpm close to idle in park or in a forward drive gear. Reverse, neutral and anything above idle while stopped or accelorating there is no rattle sound. It seems like when the engine is idle the convertion to the transmission is not completly disengaging. This is probably caused by some shop putting way too much fluid in my transmission. I’m going to siphon as much excess fuild as I can but I will need to get it inspected to become aware of any damage and serviced as soon as possible to get a new filter and fuild to try to get as much loose metal that may be floating around out of it. I’m hoping the Torque Converter is not damaged but it started making the whining sound a couple time so… I have it parked until I can get the excess fluid out. The fluid is the same color as when it was put in and no other leaks seem to be coming from anywhere. Just the ATF coming out of the fill pipe… way too much fluid, past the highest hole while below freezing… Always check your fluids and air pressure after service!
My automatic transmission makes a loud clunking sound when pitting it into gear
I just left a comment on the first question regarding your article being helpful. I put no so I could ask a question. I didn’t realize I would get this opportunity.
I have a 2003 Lexus RX300 and am having transmission/torque converter problems. I will briefly go over what I mentioned previously to you.
My car has been missing for quite awhile. When it got up to higher speeds it would operate more normally. Before the breakdown, it was missing more. We towed the car home and had it towed to Lexus to run a report. Before it was towed I started it and if I put it in gear it died. Lexus is guessing it is the Transmission and will cost around 5,000.00 + . That is about all it is worth.
A dilemma.
Thanks, Peggy