6 Symptoms of Bad Flexplate & Replacement Cost

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symptoms of bad flexplate

I borrowed my sister’s car to run some errands when I heard a loud grinding noise coming from the engine. I pulled over to check it out and realized that her flexplate had broken. A flexplate is an important part of your engine. It transfers the torque from the crankshaft to the transmission.

I knew I needed to get a new one as soon as possible. Luckily, I found one at the local auto parts store and was able to get it replaced after much hassle. That was my first encounter with a broken flexplate.

This blog post will discuss what a flexplate is, how it works, how to replace it, and its replacement cost. We will also discuss the symptoms and causes of a bad flexplate and how you can prevent it from going bad. In the end, we will answer some of the most frequently asked questions related to this topic.

What is a Flex Plate? And Where is it Located?

The flexplate is a metal plate that is located between the engine and transmission. The flexplate connects to the engine’s crankshaft and transfers the rotational energy from the engine to the transmission. It has gear teeth on its outer edge, which mesh with the starter motor, and it also has a pilot hole in the center that fits over the crankshaft. The flexplate serves as both mounts for the starter motor and a flywheel.

How Does a Flexplate Work?

The flexplate is responsible for transferring the rotational energy from the engine to the transmission. It does this by connecting to the engine’s crankshaft and spinning along with it. The teeth on the edge of the flexplate mesh with the starter motor, which helps transfer energy from the starter motor to the crankshaft and get the engine moving. When an engine is running, the flexplate remains in place on the crankshaft, but when the engine is not running and needs to be started, the flexplate is replaced by a starter ring gear. This allows the starter motor to engage with the teeth of the flexplate and spin it.

There is no flexplate in some engines, especially older gas and diesel engines. Instead, the flywheel is directly mounted on the back of the crankshaft. The starter motor then mounts to the flywheel and engages with the teeth on its edge to start the engine. This type of setup is less common in modern engines, but it can still be found in some engines today.

What Causes a Flex Plate To Go Bad?

There are several reasons why a flexplate can go bad. Some of the most common reasons are:

  1. Wear & Tear
  2. Out of Balance Engine, Transmission, and Torque Converter
  3. Missing Alignment Dowel Pins
  4. Foreign Objects in Transmission
  5. Manufacturing Defect
  6. Bent Crankshaft

Let us see these causes in a bit detail:

1. Wear & Tear:

The flexplate is subject to a lot of wear and tear. It is constantly spinning and transferring energy from the engine to the transmission. Over time, this can cause the flexplate to wear out and break.

2. Out of Balance Engine, Transmission, and Torque Converter:

An out-of-balance engine, transmission, and torque converter can cause a cracked flexplate. The three main components of the drivetrain are the engine, transmission, and torque converter. The engine produces power that is transmitted to the wheels through the transmission.

The torque converter is responsible for transferring power from the engine to the transmission. If any of these three components are out of balance and rotating at different speeds, this can cause uneven stress to the flexplate. As a result, it can be torn apart.

In addition to that, other heavy rotary components of the transmission, like front transmission pumps, may be out-of-balance that can accelerate the process of wearing on the flexplate.

3. Missing Alignment Dowel Pins:

Dowel pins are often used on flexplates to keep the plate from rotating and shifting in place. Dowel pins help secure the flexplate to the crankshaft hub, helping it stay properly aligned as it spins. If you notice that your flexplate’s dowel pin is broken, it should be replaced immediately. A fractured dowel pin can allow for greater misalignment with the crankshaft, which in turn can lead to a broken flexplate and potential engine damage.

Before you replace a flexplate with a broken dowel pin, it is important to verify that the crankshaft hub and flexplate are properly aligned. If the parts are not aligned after removing the dowel pin, it’s important to correct this alignment before installing the new dowel pin.

4. Foreign Objects in Transmission:

If there are any foreign objects in the transmission, such as dirt or metal shavings, this can cause the flexplate to become damaged. The debris can become caught in between the teeth of the starter motor and flexplate, causing them to grind against each other. This grinding can damage or even break the flexplate.

It is important to make sure that the transmission is clean before installing a new flexplate. Any debris should be removed from the transmission case, and the transmission fluid should be flushed and replaced.

5. Manufacturing Defect:

The engine and transmission are never perfectly aligned during the manufacturing of a car, there is always a slight misalignment, which is of the order of 0.2 mm, almost as thin as a hair. This misalignment keeps on increasing as time passes. But it may become severe if the inherent misalignment while manufacturing was beyond the allowable tolerance limit of 0.2 mm. When this happens, it causes the flexplate to crack and break.

6. Bent Crankshaft:

A cracked flexplate involves a bent crankshaft at times. A bent crankshaft puts uneven stress on the flexplate as it spins. This can cause the plate to warp and eventually break apart.

A bent crankshaft can be caused by several things, such as an engine overheating, a foreign object striking the crankshaft, or an improper installation. If you suspect that your crankshaft is bent, it’s important to have it inspected by a professional as soon as possible.

What are the Symptoms of a Bad Flexplate?

Now that we know the causes of a bad flexplate let’s look at some of the symptoms. These are the most common signs that your flexplate may be going bad:

  1. Clicking Noise From Starter Motor
  2. Starting Problems
  3. Grinding Noise While Idle
  4. Severe Vibrations

Let us explain these symptoms a bit:

1. Clicking Noise From Starter Motor:

If you hear a clicking noise coming from the starter motor, this is a sign that the flexplate may be going bad. The clicking noise is caused by the teeth on the starter motor trying to engage with the teeth on the flexplate but being unable to do so.

This can happen if the teeth on either the starter motor or flexplate are damaged or if the flexplate is not properly aligned with the starter motor.

2. Starting Problems:

If the flexplate is damaged, it can prevent the starter motor from engaging with the engine. This can make it difficult or even impossible to start your car.

If you are having starting problems and suspect that the flexplate may be to blame, it’s important to have the problem diagnosed by a professional as soon as possible.

3. Grinding Noise While Idle:

A bad flexplate can create a variety of strange noises from the crank and torque converter. Particularly, if the flexplate is cracked or has been damaged by debris in the oil pan, it can cause several different sounds as you drive.

One common noise caused by a bad flexplate is an odd squeaking or squealing sound near the back of the engine. This noise is usually more pronounced when you first start the engine after it has been sitting for a while. The sound may also be more noticeable when you shift gears or put your foot on the gas pedal.

Another noise that a bad flexplate can create is a knocking sound coming from the bottom of the engine. This noise is caused by the flexplate hitting against the engine block or transmission housing.

4. Severe Vibrations:

A bad flexplate can also cause your car to vibrate excessively. These vibrations are usually most noticeable when you are driving at high speeds or when the engine is under a heavy load.

The vibrations may be caused by the flexplate hitting against the engine block or transmission housing. If the problem is not fixed, it can eventually lead to damage to other parts of the engine.

How To Prevent a Flex Plate From Going Bad?

There are several things you can do to prevent your flexplate from going bad:

  • Check your engine oil level regularly and change it according to the manufacturer’s recommendations. A dirty or low oil level can cause debris to build upon the flex plate seals, which can eventually lead to damage.
  • Inspect the flexplate regularly for cracks or other damage. If you notice any damage, have the flexplate replaced as soon as possible.
  • Avoid driving your car with a low oil level. This can cause debris to build up on the flexplate and eventually lead to damage.
  • Be careful when driving over rough roads or terrain. This can cause debris to strike the flexplate and eventually lead to damage.
  • If your car has been in an accident, have the flexplate inspected by a professional. Even if there is no visible damage, the flexplate may be bent or out of alignment.

Flex Plate Replacement Cost

The cost of replacing a flex plate is dependent on several different factors. These may include the model and brand of the vehicle and whether or not you plan to replace the associated parts along with it. In general, you can expect to spend anywhere between $900 and $1,200 in order to replace this part on a typical passenger vehicle. Of course, this cost can be significantly higher if you have a luxury automobile or a high-performance sports car.

The flexplate itself is not that expensive. You can easily get one at any auto parts store in your area for anywhere from $50 to $200. The biggest cost usually comes from the labor involved with getting a new flexplate installed. Most mechanics charge anywhere from $500 to $950 for this service, so if you don’t have a flexible budget, it’s crucial that you research the prices in your area before you commit to the work.


A flexplate is a thin metal plate that sits between the engine and transmission in a car. It helps to transfer power from the engine to the transmission, and it also helps to keep the engine and transmission aligned.

The symptoms of a bad flexplate include excessive vibrations, engine misfires, and difficulty shifting gears. If the problem is not fixed, it can eventually lead to damage to other parts of the engine.

You can do several things to prevent your flex plate from going bad. These include checking your oil level regularly, inspecting the flexplate for cracks or damage, and avoiding driving over rough roads or terrain.

In a nutshell, a flexplate is a critical component in your car’s engine, and it’s important to be aware of the symptoms of a bad flexplate so that you can take steps to prevent it from going bad. By following the tips in this article, you can help prolong the life of your flexplate and avoid having to replace it prematurely.

Frequently Asked Questions

What is the difference between a flywheel and a flexplate?

Flywheels and flexplates serve the same purpose eventually. A flywheel is used in a conventional manual transmission setup, whereas on the other hand, a flexplate is a thing of automatic transmission.

Flywheels and flexplates both serve the purpose of transferring energy from the engine to the transmission in a vehicle along with a pressure plate. The main difference between the two is that flywheels are made of heavier materials and are able to withstand more heat and friction than flexplates. Flexplates are also much thinner because they don’t have to store as much energy.

There are slight differences in the design of the two as well. Flexplates do not feature any friction surface as a flywheel does, and they also use different bolts to mount them to the crankshaft. Overall, flywheels and flexplates each have their own advantages and disadvantages when it comes to performance in vehicle engines.

Can you drive with a broken flex plate?

No, you cannot drive with a broken flex plate in your car. The flexplate is what connects the engine to the transmission, and without it, your car won’t be able to move. So if you have a broken flex plate, you’ll need to get it fixed before you can drive again.

If your flex plate is broken, it’s likely because there was a problem with the way it was installed or because it’s been damaged from overuse. Either way, it’s important to get it fixed as soon as possible so you can avoid further damage to your car.

What is the average lifespan of a flexplate?

The average lifespan of a flexplate is about 100,000 miles. However, it is not uncommon for them to last much longer. Flexplates are made from tough materials and are designed to withstand a lot of wear and tear. With proper maintenance, they can last a very long time.

Why flexplate is called a flexplate?

Flexplates are called flexplates because it has the ability to flex under load. The alloy steel that is used to make a flexplate also has many other characteristics such as toughness, ductility, magnetic permeability and resistance to abrasion, etc.

A well-designed flexplate is essential for any performance engine because it’s what transfers the power from the engine to the transmission. A flexplate that is not designed properly can cause all sorts of problems such as power loss, vibration, and even failure. That’s why it’s important to choose a quality flexplate when building or upgrading your engine.

Can you repair a cracked flexplate?

Yes, a cracked flexplate can be repaired. However, it is important to note that the repair may not be permanent, and the flexplate may eventually need to be replaced. If you plan to repair a cracked flexplate, it is important to consult with a mechanic or automotive specialist to ensure that the repair is done properly and will not cause further damage to your vehicle.

How long can you drive with a cracked flexplate?

This is a question that many people have asked, and it can vary depending on the severity of the crack. In general, you should not drive your vehicle if the flexplate is cracked or broken.

A cracked flexplate will not be able to hold up under the torque produced by your engine and could lead to dangerous consequences such as loss of control or an accident. If you must drive with a cracked flexplate, take extra care to avoid any sudden starts or stops.

How to check if the flexplate has gone bad?

You can check if your flexplate has gone bad or not with the help of a stethoscope. You simply need to turn on the engine and place the stethoscope on the underside of the bell housing. If you hear any rattling noise, it indicates that the flexplate has gone bad and needs to be replaced.

Another way to check for a bad flexplate is by looking for cracks or damage. If you see any cracks, then it’s likely that the flexplate has been damaged and needs to be replaced.

Can a cracked flexplate cause a bad torque converter?

It’s possible that a cracked flex plate could cause issues with the torque converters, but it’s not necessarily the direct cause. If the crack is severe enough, it could cause the converter to bind up and not function properly. However, there are other potential causes for converter problems, so it would need to be diagnosed by a professional to determine the root cause.

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