Symptoms Of A Bad Flywheel And The Replacement Cost

A huge, thick clutch component called a flywheel has the appearance of a giant disc. It is connected to the engine’s crankshaft and ensures that power from the motor is delivered smoothly. It balances changes in engine speed and dampens crankshaft vibrations while storing extra energy for later use.

For instance, when the driver releases the accelerator pedal, this energy keeps the engine going. In manual transmission automobiles, these parts link the engine to the transmission, allowing the clutch to transmit power to the wheels. Also, it will be much more challenging to shift gears if the flywheel is destroyed correctly, which could harm the clutch irreparably.

What Is The Purpose of Flywheels in Automobiles?

The flywheel, a crucial part of an engine, regulates the crankshaft’s speed to lessen vibrations and to smooth and balance the power strokes. When the machine starts, gear teeth on the flywheel’s circle mesh with a tiny Bendix gear. This aids in creating the compression cycle, and once it has finished, the Bendix gear separates, allowing the flywheel to spin freely.

A flywheel is used to help provide smoother and more efficient engine operation by maintaining crankshaft rotation speed. This results from the piston’s inertia between firings, which lessens the rocking motion by pistons firing at an angle to the crankshaft.

Also, it’s mass damping vibrations and mounting on mounts reduces stress on drivetrain components, including universal joints that change angles when turning, axle couplings, and parallel transmission shafts.

New flywheel for car automatic transmission.

Flywheels are crucial engine parts with several benefits, including enabling engines to start using their Bendix gears, enhancing engine efficiency and smoothness, lowering vibrations, and minimizing wear and tear on drivetrain components. All of these activities help engines run more efficiently.

8 Bad Flywheel Symptoms

Flywheels unfortunately do not endure forever. As they are routinely used in the car, they gradually deteriorate. You will only be able to notice specific obvious indications if your flywheel becomes worn out or broken.

Allowing these symptoms to persist too long will affect the car’s general drivability. Here are a few of the most typical warning signals of a damaged flywheel.

1.     Having trouble starting, or starting irregularly

If the teeth are broken, the flywheel may have problems connecting with the starter motor. Starting the car could be challenging or impossible as a result. You should check your starter if you have trouble starting your vehicle.

2.     Engine Stagnation

Stalling the car will be much simpler, and it might idle rough if the aftermarket flywheel is too light for the vehicle (or the driver). Pushing the clutch in may even cause the car to stall on very lightweight flywheels because the engine speed lowers too quickly for the ECU to provide more fuel and air to make up for the loss in speed.

3.     Engine Rumbling When the Clutch is Engaged

An uneven flywheel may cause vibrations across the entire powertrain, even when the clutch is engaged. Ensure all bolts were torqued to specifications if you recently changed the clutch, flywheel, or pressure plate, and use a thread locker if the factory service manual recommended it.

Auto mechanic working on car automatic transmission in auto repair shop.

Because the flywheel contains a significant amount of energy, it is quite dangerous if it becomes loose or breaks apart while the vehicle is moving.

4.     Slippery Elements

Gear slippage is what happens when you change gears and then find that your ground speed increases considerably more slowly than the engine speed (RPM). A slipping flywheel may feel like a slipping clutch because the friction surfaces on the pressure plate and the flywheel are both made to grip the clutch.

Even when the clutch should be fully engaged, if oil or grease were to get on the flywheel’s friction surface, it would affect the clutch’s ability to engage with the flywheel and grab it without slipping. When you shift gears, if the equipment keeps falling, it will undoubtedly affect your driving skills and cause clutch damage.

5.     Burning Odor

If there is a burning smell that consumes your passenger cabin, this could be attributed to many possible causes. A bad flywheel could be one of those causes because of all the heat generated from the friction in the clutch.

If you have used the clutch at times when you weren’t supposed to, this could cause problems with the flywheel.

6.     Movement of the Clutch (Clutch Chatter)

If the clutch pedal vibrates a lot, the flywheel must be replaced. At some point, the vibrations will become so severe that you won’t just feel them coming from the clutch pedal but also from the floor. The flywheel in your car may develop excessive runout as you drive, which causes the surface to feel distorted when you press the clutch.

Foot pressing pedals of a car to drive.

You have likely damaged the flywheel due to extreme heat or metal-on-metal wear if you have ever overheated your flywheel or driven too long with a clutch past its prime. The flywheel will be harmed by clasps worn to the rivets.

The metal is heated well over its operating temperature in a broken flywheel, giving it a bluish hue. Very likely, the surface will also have a few hairline cracks. Due to the flywheel’s heating and cooling, metal streaks might be on the surface.

Spring-loaded flywheels include twin-mass flywheels. The flywheel’s springs may be the source of these vibrations if your car has one of these. As they cannot be resurfaced like a regular flywheel, dual-mass flywheels will probably need to be replaced.

7.     Improper maintenance

Other parts may suffer damage or alignment issues if replacement starters or clutches are incorrectly put in. To further emphasize this point, replacing the clutch as soon as possible is strongly advised if it sustains damage. Grips are significantly simpler and less expensive to replace than flywheels, which will be affected if you leave them.

8.     Cannot Change Gears

You may experience the opposite issue with your gears. Your gears won’t slip; instead, you won’t be able to shift at all. The flywheel must be in pretty terrible health for this symptom to appear, and other transmission parts might also be harmed. Naturally, you won’t be able to drive your car at all if you cannot change gears.

Is It Okay To Drive With A Bad Flywheel?

If the damage is modest, driving with a defective flywheel is possible. Yet, this does not imply that doing so is wise. The problem can result in more severe harm to the engine’s crankshaft, clutch parts, and the machine itself.

The engine will feel more vibrations, which will lower its overall performance. Also, you should get a professional car inspection when you suspect clutch trouble.

Is It Possible To Have It Repaired?

Dual-mass wheels typically need to be replaced because grinding procedures might damage the interior components, whereas single-mass flywheels can usually be repaired. After all, the surface of the details can be restored.

Because replacing the clutch at the same time as the flywheel is frequently required, things might start to get pricey. Fortunately, there are many inexpensive clutch kits available on the market.

How To Replace a Bad Flywheel?

Your flywheel has to be changed if it is fractured or damaged. Replacement is a simple process, although it can take some time. We will demonstrate how to replace a damaged flywheel.

1.     The gearbox cover must be taken off first. You can accomplish this by unfastening the bolts holding them in place and drawing it out. You can see the flywheel once the transmission cover has been removed.

2.     The flywheel needs to be taken out next. The bolts holding it in place can be taken out in order to accomplish this. Each bolt must be replaced in the same order, so keep track of where each goes.

3.     The new one can be installed after the flywheel has been removed. Bolts will be included with the new flywheel, so you won’t have to worry about looking for replacements. The replacement flywheel can be installed by simply doing the same process backward.

4.     You must torque the bolts after installing the new flywheel. A torque wrench can be used to accomplish this. The installation instructions for your flywheel will specify the torque requirements.

5.     Reinstall the transmission cover once the bolts have been torqued. Installing the transmission is as simple as doing the same processes backward.

Flywheel Replacement Cost

Depending on the make and model of your car, the cost to repair the flywheel can change. Nonetheless, the typical cost of replacing a flywheel is between $600 and $900. The eventual cost of a new flywheel can depend on a few different factors. The final price will depend on several factors, including the kind of vehicle, labor charges, and the part’s quality.


The flywheel of an automobile is a vital part that keeps it operating properly. If it isn’t functioning correctly, the car won’t work well or might not run. Difficulties changing gears, shaking or rattling, and grinding noises are signs of a faulty flywheel.

Your transmission may need expensive repairs as a result of a bad flywheel. Verify that the flywheel is the problem if you observe any symptoms rather than the clutch. To do this, you must diagnose the car and examine the error codes it has returned. If your flywheel is broken, you shouldn’t keep driving since you risk losing control of your vehicle.

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About Brock Rangel

Hi, I am Brock, and I am the lead editor/photographer for TheCarColony. I have been a mechanic for over 14 years now, and I am here to spread my car knowledge across the web!