The torque converter is a vital component in vehicles with an automatic transmission system. It allows a vehicle to shift between gears automatically.
Every automatic transmission vehicle relies on the torque converter for power and if this component starts failing, you will notice symptoms like slipping transmission or poor gear shifting.
The torque converter converts the rotating power generated by the engine to mechanical power to ensure smooth and hassle-free driving.
This article will explore everything you need to know about the torque converter, ranging from its working principle to functions, the causes of a torque converter failure, and lots more.
What is a Torque Converter and How Does it Work?
The torque converter is a component that allows a vehicle to automatically shift between gears by converting power from the engine into hydraulic pressure that controls this shifting process. The component multiplies the torque when it’s at low RPM to ensure the power output in the engine is at its optimum range.
The torque converter transfers the rotational power of the engine torque to the transmission. It is mounted on a flex plate installed between the engine and transmission. A conversion effect is created when the crankshaft spins the flex plate.
There is a pump that contains a bunch of blades, just under the cover of the torque converter. When these blades spin, fluid from the transmission flows on the blade impeller. The hydraulic pressure generated in this process will determine the gear and speed of your vehicle.
The torque converter assembly is made of five primary components. These include the stator, turbine, clutch, impeller, and front cover. All these components work together to ensure gear shifting is smooth and your vehicle does not stall when you want to stop.
Signs of a Bad Torque Converter
Problems with the torque converter are sometimes mistaken to be transmission problems which will make a car user spend a huge amount of money on changing the transmission system.
Here are some noticeable signs of a bad torque converter.
Check engine light illuminates
The torque converter is controlled by the transmission control module (TCM).
When the module detects a problem with the torque converter, it will trigger the check engine light and cause the dashboard to display some trouble codes related to a faulty torque converter.
Stalling and shuddering
A bad torque converter can cause the clutch to lock up and when this happens, you will experience the car vibrating, shuddering, or stalling when you want to stop.
If your vehicle vibrates while driving at 30 or 45 mph, it indicates there might be a problem with the torque converter.
A bad torque converter will not manage fluid properly. It’s either too much hydraulic fluid or too little fluid that is sent into the transmission system. This will cause the transmission gear to become slippery.
Inconsistent transmission shifting
A faulty torque converter will deliver incorrect output that will cause the transmission to inconsistently increase or decrease the speed of your vehicle. This problem can make driving very dangerous.
As such, when you notice this problem, take your vehicle to an auto repair shop for proper attention.
Poor gear shifting
An issue with the torque converter will cause delays when you want to shift gear.
When the pressure output of the torque converter is low, the transmission will be slow and sometimes rough.
Unusual noise from the car
When the converter torque is bad, you might hear some rattling or whining noise from your car.
The clutches in the torque assembly will cause loud noises, especially when the vehicle is in park mode.
Contaminated or leaking transmission fluid
The role of the transmission fluid in the torque converter is to create pressure in the component to ensure that transmission is smooth and easy. If the transmission fluid turns dark or burnt and has debris or metal particles in it, it means the fluid is contaminated and will hinder the effectiveness of the torque converter.
Also, transmission fluid is essential to the functioning of the torque converter. If the torque converter’s seal is worn out, it will cause fluid to leak out, leading to issues with the torque converter of your vehicle.
The temperature gauge connected to the transmission will enable you to know when the component has overheated.
When the gear slips, the transmission fluid will heat up and even boil in some cases. An overheating transmission is one of the symptoms of a faulty torque converter and can cause further damage to the transmission system if ignored.
Loss of acceleration
If your vehicle struggles to accelerate when you match the gas pedal it could be an indicator of the torque converter failure.
When this happens, it is important to conduct a visual inspection first as other components like the transmission can also cause a similar problem.
Causes of Torque Converter problems
Several factors can lead to torque converter problems, and it is important to be familiar with them.
Some causes of torque converter problems are discussed here.
Damaged torque converter clutch solenoid
The torque converter clutch solenoid is responsible for controlling fluid pressure and how much fluid gets to the lockup clutch. If this component becomes faulty, it will fail to measure the exact quantity of transmission fluid needed, thereby leading to abnormal fluid pressure in the transmission system.
Bad needle bearings
The torque converter’s bearings can wear out and cause transmission problems. Also, loose bearings can cause noise while driving. The needle bearings separate the impeller, stator, turbine, and converter housing. Apart from the noise, the needle bearing can shed some metal chips into the transmission fluid leading to its contamination.
Worn-out torque converter seals
A broken torque converter seal will cause the transmission fluid to leak from its housing. Leaking transmission fluid will make it difficult for the torque converter to transfer power from the engine to the transmission. This can result in stalling, overheating, and slipping.
Faulty torque converter clutch plate
A damaged converter clutch plate will cause the torque converter to lock up while in drive or idling gear and will affect transmission.
How to Test the Torque Converter
Before going ahead to replace the torque converter, it is important to test it first. This is vital because other components can display similar symptoms when faulty.
Here are the steps to take while testing the torque converter.
- Start your engine and let it warm up: The first step to take is to turn on your engine and allow it to warm up to about 40 degrees before moving further. It might take a little time to get to 40 degrees and you should ensure the fluid is warm enough before moving to the next step.
- Engage the drive gear: Apply the drive gear and pay attention in case noises are coming from the torque converter. Press the accelerator pedal lightly to move the car forward and shift between gears. Pay attention to the sounds coming from the converter. If you don’t notice anything strange while doing this, proceed to the next step.
- Test drive: To test drive the car after making all necessary adjustments you will need to increase the speed of the car. Monitor the speedometer and tachometer as well. If the engine revs up but the car isn’t accelerating, it could mean the torque converter is slipping. After test driving, you will know what steps to take next to ensure your torque converter starts functioning well.
Cost of Replacing the Torque Converter
Replacing the torque converter is not as expensive as replacing the transmission system.
You must check to confirm if the problem is from the torque converter and not the transmission before going ahead to replace as both can have similar symptoms. The cost of replacing the torque converter varies based on the model and make of your vehicle.
A new torque converter torque costs between $100 to $400 while labor hangs around $200 to $2,000, amounting to $300 to $2,500 for both parts and labor.
Frequently Asked Questions
Where is the Torque Converter located?
The torque converter is a round-shaped component that can be found between the transmission and the engine’s flex plate inside the engine compartment.
What does a bad Torque Converter sound like?
When your torque converter is bad, you can hear rattling or whining noises coming from your car. If it’s the torque converter’s clutch that is damaged, you will hear loud rattling noises coming from the component.
Will a bad Torque Converter throw a code?
Yes. However, it happens less often because only problems related to the torque converter’s clutch tend to throw a code on the dashboard. Other issues might not throw a code.
Can a bad Torque Converter damage transmission?
Yes! A bad torque converter can damage the transmission. When the torque converter is bad, it causes overheating, excessive friction, and contamination of transmission fluid. A faulty torque converter can also cause the transmission fluid to leak. All these can lead to transmission problems. A damaged torque converter can even cause more serious internal issues to the transmission.
Can a Torque Converter be repaired?
This is very uncommon because it’s not an easy task to do. Very few companies specialize in doing this and it will cost a lot of money as well. When your torque converter is damaged, replacement is always the most likely option. The torque converter is made up of several parts, therefore, it’s not always possible to repair some parts and leave out others.