A bad torque converter is a serious and costly transmission problem that should be fixed ASAP.
If left unchecked, it can cause gear slipping, rough idling, or even vehicle control loss, posing serious safety risks.
Diagnosing bad torque converter symptoms early can help avoid major inconveniences and expensive repairs.
Wondering how to spot the signs?
In this guide, we’ll cover the key symptoms of a bad torque converter, explore what causes it to fail, and walk you through how to fix the issue.
This Article Contains
- 6 Serious Symptoms of a Bad Torque Converter
- 6 Common Reasons a Torque Converter Goes Bad
- How to Diagnose and Fix a Bad Torque Converter
- 3 FAQs on Torque Converters
6 Serious Symptoms of a Bad Torque Converter
A torque converter is pivotal in transferring power from the engine to the transmission. If it fails, the following symptoms can help you identify the malfunction:
1. Gear Slippage
A slipping transmission often feels like the engine is revving faster than the car’s speed. This can lead to power loss, rough gear shifts, or even skipped gears while driving.
2. Loss of Acceleration
This transmission issue can occur when engine power isn’t properly transferred to the transmission, causing the engine RPM to rise higher than the vehicle’s speed. As a result, the car can feel very sluggish while driving.
3. Trouble Shifting Gears
If you experience a rough gear change or can’t shift gears at all, the issue may lie with the torque converter solenoid.
When this component wears out or fails to engage properly, it can disrupt the smooth power transfer between the engine and transmission, making gear shifts difficult or jerky.
4. Rough Idling
If you experience rough idling, along with sudden jolts or vibrations while the vehicle is in gear but not moving, a malfunctioning torque converter is likely the culprit.
5. Excessive Jerking and Shuddering
A failing torque converter can also cause shuddering during acceleration, leading to sudden jolts even on smooth roads. This often stems from contaminated transmission fluid or a malfunctioning lock-up clutch.
6. A Strange Noise From the Vehicle
If you can hear a loud, strange noise like grinding or whirring while accelerating (but not while idling), it could be an issue with the needle bearings in the torque converter.
But what causes torque converter trouble in the first place?
Let’s take a look at some of the causes.
6 Common Reasons a Torque Converter Goes Bad
While your vehicle’s torque converter is made of billet steel, despite its sturdiness, the internal components are prone to failure.
Here are a few of the most common reasons behind it:
1. Overheating Transmission
A torque converter requires a temperature of around 175 to 200° F to function properly.
An overheating transmission can damage the torque converter by degrading transmission fluid and breaking down internal seals. Since the converter relies on hydraulic pressure and fluid friction to transfer power, excessive heat can lead to fluid leaks, clutch slippage, and internal damage.
2. Problematic Clutch Plate
The clutch plate sits between the flywheel and the pressure plate in manual transmission vehicles.
When you press the clutch pedal, the pressure plate pulls away, disengaging it and cutting off power flow from the engine to the gearbox. Releasing the pedal re-engages the clutch, allowing power to flow again. Some torque converters have a lock-up clutch that engages at higher speeds for better fuel efficiency.
If there is clutch damage, it may slip or fail to engage, leading to a serious transmission problem like overheating, poor performance, or torque converter failure.
3. Faulty Torque Converter Bearings
The torque converter bearing allows the gear shaft to rotate smoothly, minimizing friction and preventing grinding.
Worn or damaged bearings inside the torque converter can cause internal components to grind against each other, resulting in loud, unusual noises. This creates metal debris in the transmission fluid, increasing friction, overheating, and wear throughout the torque converter system.
4. Wear and Tear in the Seal
The seal between the torque converter and the transmission pump can wear out over time. Even a small transmission fluid leak can reduce fluid pressure, which is critical for the torque converter’s hydraulic operation. This can cause slipping, shuddering, and long-term damage.
5. Failing Torque Converter Clutch Solenoid
A torque converter clutch solenoid controls the flow of transmission fluid that engages and disengages the clutch. Any damage to the solenoid can cause the clutch to lock up at high or low speeds. This can lead to poor fuel efficiency and potentially damage the torque converter.
6. Contaminated Transmission Fluid
Transmission fluid lubricates the transmission and its internal components for smooth and optimal performance. So, it must be regularly changed to ensure proper function.
If the trans fluid is contaminated with metal shavings or has a brown, milky appearance, it can lose viscosity and damage the torque converter due to high friction.
Now that we’ve covered all the symptoms of a bad torque converter and its causes, let’s look at how to diagnose and fix the issue.
How to Diagnose and Fix a Bad Torque Converter
If you’re noticing signs of a malfunctioning torque converter, it’s a good idea to confirm the issue before heading to an auto repair shop.
While fixing the torque converter trouble involves complex components that a trained technician should handle, there are a few tests you can carry out on your own to get a better idea of what’s wrong:
- Look for signs of damage: Inspect the transmission and its surrounding areas. If you notice a transmission fluid leak (a pool of bright red fluid), it’s likely due to a worn-out seal or gasket.
- Conduct a stall speed test: A stall speed test can help you check the torque converter’s condition in rear-wheel-drive vehicles. Here’s what you need to do:
- Engage the parking brake and shift the car into ‘Drive’.
- Press the brake pedal and gradually increase the throttle.
- Note the RPM when the vehicle lurches — this is the stall speed.
- Compare it to your manual’s specifications to see if they match.
- Watch out for unusual noises: If the transmission area makes a loud, rough noise, call a professional immediately to get the torque converter checked.
Remember, driving with a torque converter problem is a serious safety risk. So, once you’ve done a self-check, get a mechanic to confirm the issue and perform the required repairs.
Here’s how the mechanic will perform a replacement:
- Remove the faulty torque converter and inspect the area for other potential issues.
- Examine the new torque converter to ensure the seal is intact and free from manufacturing defects. Then, they’ll install the new unit, flush the transmission to remove old fluid, and refill it with fresh Automatic Transmission Fluid (ATF).
- Check if components, such as the stator splines, turbine splines, and pump gear, function properly.
- Test the vehicle and tune it to the recommended adaptive settings to avoid future damage to the torque converter.
Got more questions?
Check out these FAQs.
3 FAQs on Torque Converters
Here are the answers to some common questions about torque converters:
1. What Is a Torque Converter and How Does it Work?
A torque converter is a fluid coupling, also known as a hydraulic coupling, and sits between the engine’s flex plate and transmission in an automatic vehicle. It prevents the engine from stalling when the car is idling and boosts torque during acceleration to improve pulling power.
It looks like a metal donut and contains five main parts: the impeller, turbine, stator, clutch, and front cover.
The impeller (connected to the engine) has curved blades and pushes transmission fluid to the turbine, which drives the transmission. The stator redirects the fluid to increase force and improve efficiency.
2. How Much Does a Torque Converter Replacement Cost?
Replacing a bad torque converter can cost between $600 and $2000.
This includes:
- Cost of parts: 430 to $1200
- Labor: $170 to $800
However, the prices vary widely based on location, labor costs, mechanics’ experience, and the vehicle’s model.
NOTE: Although rebuilding the entire transmission system or the torque converter is possible, it’s generally not recommended. If done improperly, rebuilt parts can lead to torque converter failure, transmission problems, and engine damage. In the long run, replacing the torque converter is often more cost-effective.
3. Is It Safe to Drive with a Bad Torque Converter?
No, not at all!
The torque converter is the bridge between the engine and the transmission. Driving with a damaged unit can lead to gear change issues, a slipping transmission, and reduced engine performance.
In severe cases, transmission problems arising from a torque converter issue can snowball into complete transmission failure, which can be expensive to replace.
Fix Your Bad Torque Converter with AutoNation Mobile Service
A torque converter is the soul of your automatic transmission vehicle, and you don’t want it to lose its fizz.
If you notice any unusual noise or other signs of a torque converter failure, contact experts like AutoNation Mobile Service immediately.
We’re a mobile auto repair solution offering upfront, transparent pricing and a 12-month, 12,000-mile repair warranty. Our trained technicians come to you with high-quality equipment and repair your vehicle on-site.
So what are you waiting for?
Contact us today to book a service.