Dual mass flywheels appear to be a better option than single-piece flywheels, especially due to the absence of noise and vibrations. However, the component requires a nice driving style to maintain its efficiency and reach its lifespan.
Therefore, once the component suffers from a bad driving style for a while, it will result in an unexpected malfunction in the long run. So, this article unveils all you need to learn about dual mass flywheel symptoms and how to fix the problem.
What Is a Dual Mass Flywheel and How Does It Work?
The dual mass flywheel represents an engineering solution to a fundamental problem in modern diesel and high-torque gasoline engines.
Unlike traditional single-mass flywheels that consist of one solid piece of metal, dual mass flywheels contain two separate masses connected by an internal spring and dampening system.
The primary mass connects to the crankshaft, while the secondary mass attaches to the clutch assembly.
This sophisticated design isolates engine vibrations and torsional pulses before they reach the transmission. The internal springs absorb the irregular firing patterns common in diesel engines and the low-RPM torque pulses from turbocharged gasoline engines.
From my experience, vehicles equipped with dual mass flywheels deliver noticeably smoother operation at idle and during acceleration compared to older single-mass designs.
The complexity that provides these benefits also creates vulnerability. The internal springs, lubricant, and bearing surfaces wear over time, eventually leading to failure.
Understanding the symptoms helps you catch problems early and avoid secondary damage to your clutch and transmission.
symptoms Of Dual mass flywheel
If your car has a dual-mass flywheel, you may notice some of the following symptoms if it starts to fail:
#1. Hard Clutch Pedal.
If you notice that the clutch pedal is getting harder to press, it could be a sign that the dual-mass flywheel is starting to fail.
This is because the flywheel springs cannot dampen the vibrations as effectively, making it harder to press the pedal.
Now hard clutch may be caused by other problems such as a worn pressure plate or a bad clutch cylinder, but it is also a symptom of a bad dual-mass flywheel.
#2. Problems Shifting Gears.
A bad dual-mass flywheel can make it difficult to shift gears in your car. This is because the flywheel absorbs engine vibrations, which helps improve shifting performance by reducing wear and tear on other transmission components.
Without a proper functioning dual-mass flywheel, it may be difficult for you to shift gears smoothly. If you notice any unusual noise or difficulty shifting gears, it’s important to have your car checked by a mechanic to ensure that the dual-mass flywheel is not the cause.
#3. Torsional Vibrations.
Torsional vibrations are caused by the twisting force of the engine’s crankshaft. These vibrations can be amplified by a failing dual-mass flywheel, causing a shaking or vibrating sensation in the car.
This can be a very dangerous problem as it can cause damage to other parts of the car if left unchecked.
#4. Rattling Sound.
If you hear a rattling sound coming from the engine bay, it could be a sign that the springs in the dual-mass flywheel are starting to fail.
This is because the springs are not able to effectively dampen the vibrations of the engine, causing them to rattle. You may hear other types of noise, such as grinding or squeaking.
The reason behind such noise is that, with time and usage, the grease inside the flywheel starts to dry out and gets accumulated in other parts of the car. This makes it difficult for the flywheel to rotate smoothly, causing a rattling sound.
If you notice any of these symptoms, it’s important to take your car to a mechanic as soon as possible.
#5. Slipping Clutch.
One of the most serious symptoms of a bad dual-mass flywheel is a slipping clutch. This may happen due to three main reasons:
- The dual-mass flywheel is not properly balanced. This can cause the engine to vibrate excessively, which can cause the clutch to slip.
- The dual-mass flywheel is worn out. This can cause the clutch to slip due to a less effective friction surface between the dual-mass flywheel and the clutch disc.
- The dual-mass flywheel has developed delamination, which will cause the clutch to slip because of excessive heat build-up in the transmission.
A slipping clutch can lead to serious damage to the transmission and other drivetrain components if not addressed quickly. If you suspect that your dual-mass flywheel is causing your slipping clutch, it is important to have it replaced as soon as possible.
What Causes a Flywheel to Wear Out?
Aside from age, other factors can cause the flywheel to wear out faster than its intended service life.
#1. Contamination.
Oil or grease contamination can significantly reduce a flywheel’s efficiency, as it can cause the flywheel and clutch to slip.
#2. Improper Installation.
Misalignment, imbalance, and inadequate torque can negatively impact the flywheel’s performance.
To avoid these issues, it’s best to leave flywheel replacement at the hands of an experienced professional. Flywheel replacement might not be the easiest task for an average DIYer, and doing it poorly can result in more issues down the road.
#3. Overheating.
The flywheel can only endure so much. Poor driving practices and car maintenance can accelerate wear on several components, causing the engine to overheat.
When this happens, the flywheel can warp under extreme heat and develop cracks on the surface.
How Do You Test for a Bad Dual Mass Flywheel?
If you’ve been noticing the telltale signs of a bad dual-mass flywheel, like rattling, a stiff clutch pedal, and vibrations when you’re in neutral, you usually have to remove it from the car to test it.
However, there is a special dual-mass flywheel test tool. It’s sold at some auto parts stores and is often available via special order.
Once you have it, you can use the DMF test tool and the following steps to determine if your dual-mass flywheel assembly is bad, or if there’s some other fault in your clutch.
- Step One: Back the car up and block it off for safety.
- Step Two: Locate the clutch and look for signs of grease, scoring, or corrosion around it and the dual-mass flywheels.
- Step Three: Feel how much friction there is on the flywheel.
- Step Four: Mount the testing tool to the dual-mass flywheel. If there is an even number of mounting bolts you can attach it centrally. This will allow you to measure the degrees of variance.
- Step Five: Make sure the locking docks lock the flywheel. This will keep it from rotating while you use the degree gauge on the DMF testing tool.
- Step Six: Move the tool’s arm counterclockwise, pushing against the force of the springs until it stops.
- Step Seven: Release the arm of the DMF tool and let it settle back on its own.
- Step Eight: Mark the degree gauge at zero. This will have the tool calibrated to your car’s DMF.
- Step Nine: Push the handle to move it counterclockwise until the spring force stops it.
- Step Ten: Then, read the degree on the face of the tool.
- Step Eleven: Check the tolerance for the DMF in your car’s repair guide. For most, the acceptable limit is 20 degrees or less.
- Step Twelve: You can then start measuring the rock of the bearings by attaching the dial gauge to the test arm. This will create a triangle configuration of the tool’s components.
- Step Thirteen: Then very lightly push on the DMF tool’s arm toward the engine. When it settles firm, set the dial gauge to zero.
- Step Fourteen: Pull back gently with the same force until it settles firmly, and check the degree of rock the bearings allow. For most, the degree of tolerance is 1.6 millimeters or less.
How Do You Fix Dual Mass Flywheel?
If your vehicle’s DMF suddenly fails, it may cause severe damage to other parts in the long run. Therefore, it is advisable to fix it before things get out of hand. However, fixing a defective dual mass flywheel requires a complete replacement of the part.
The process can be a bit complex, requiring the expertise of a professional auto mechanic. So, you may want to contact one instead of doing the job by yourself as a DIYer.
However, if you’re an expert mechanic, you can save costs by doing the job yourself. Kindly follow these recommendations to fix your vehicle’s DMF failure.
#1. Replace the old DMF with the correct OE-spec DMF.
Replacing the old dual mass flywheel is the first option for fixing a DMF failure. However, replacing the old DMF with the OE-spec can be pretty expensive than switching to a single-piece flywheel.
Nonetheless, it will restore your car’s stock performance and the exact feeling, like your old DMF never failed.
If your car’s dual mass flywheel just failed, getting a suitable OE-spec replacement for the component is worth it. However, if your budget cannot accommodate this option, you can consider the next option below.
#2. Convert the old dual mass flywheel to a single flywheel.
Converting your old DMF to a single flywheel is another amazing way of fixing the mass flywheel failure. This is a perfect fit, especially if you have altered the vehicle’s horsepower by increasing it for more power output.
Also, if you engage in heavy towing or hauling, switching to a single-piece flywheel will be more durable for the job.
Besides the durability of the component, replacing the component now or later in the future will be more economical than an OE-spec dual mass flywheel.
If you currently have a defective dual mass flywheel, ensure to consider both options critically before making a final decision.
Kindly consider your vehicle’s major function and the financial implication of opting for an O3-spec dual mass flywheel before concluding on either option.
Replacing A Dual Mass Flywheel vs Converting to A Single Mass Flywheel
Like a lot of the parts on the modern automobile, dual mass flywheels are a compromise. On the plus side, dual mass flywheels reduce the torsional vibrations in the driveline and the other related vibration and noises.
On the negative side, dual mass flywheels are expensive and more prone to failure than simpler, single mass systems (especially if a vehicle is modified to have increased torque).
Single mass conversion kits replace a dual mass flywheel with a simpler, more robust system. While a single mass system will be a bit noisier than a dual mass system, it will also be more reliable, especially in high torque/low idle rpm applications.
Gear Rollover Noise (aka Gear Rattle): The sound that a manual transmission makes when the gears in the gear box are in neutral and are shaken ever so slightly by the engine. It sounds like a light knocking or growling sound, and has absolutely no negative effect on the transmission’s performance or durability. The Gear rollover noise only occurs when the vehicle is idling and the transmission is in neutral.
At Phoenix Friction Products, we offer a variety of single mass flywheel conversion kits. Some of the kits are offered by the Tier 1 OE clutch manufacturers, and some we engineer and then extensively test.
In fact, we test all of the single mass conversion kits in-house, ensuring that these kits are more reliable than the dual mass units they replace.
We also work hard to ensure these single mass kits don’t negatively impact drivability our testing procedure and metrics for success are reliability, smooth shifting, no increased pedal effort, and as little noise as possible compared to the OEM dual mass units.
Maintenance Tips to Extend Flywheel Life
Master Smooth Clutch Technique
The single most effective method for prolonging dual mass flywheel life involves developing smooth, deliberate clutch engagement habits.
Release the clutch pedal gradually and consistently, allowing the clutch to engage progressively rather than suddenly. This technique reduces shock loads on the flywheel’s internal dampening system and minimizes heat generation.
Avoid slipping the clutch to hold position on hills or in traffic. Instead, use your brake pedal to maintain position and only engage the clutch when ready to move.
Extended clutch slippage generates excessive heat that damages both the clutch disc and the flywheel’s internal components.
Rev-Matching During Downshifts
When downshifting, practice rev-matching by briefly applying throttle to bring engine speed closer to the transmission speed before engaging the clutch. This technique reduces the synchronization load on both the transmission and flywheel.
While modern synchronized transmissions don’t require perfect rev-matching, the practice significantly reduces component stress and extends service life.
Proper Engine Warm-Up
Cold engines produce more irregular combustion and higher internal friction, both of which increase stress on the dual mass flywheel.
Allow your engine to warm up for 30-60 seconds before driving, and avoid aggressive acceleration until the engine reaches normal operating temperature. This simple practice reduces wear on numerous engine and drivetrain components, including the flywheel.
FAQs.
Q: Can you drive with a faulty dual mass flywheel?
Driving with a faulty dual mass flywheel is possible. However, it would be best if you didn’t consider it because of its effects. A faulty dual mass flywheel is characterized by rough idling and unexpected misfire.
Also, a faulty dual mass flywheel usually produces a rattling sound except when you press down the clutch. This occurrence will hinder the proper functioning of your vehicle until you fix the problem. Besides, a bad dual mass flywheel sound can be frustrating.
So, if you have a faulty flywheel, ensure to contact a professional auto mechanic to fix it. However, always remember that the extent of a car’s dual mass flywheel lifespan is dependent on the owner’s driving style.
Q: Should I change DMF with clutch?
Yes, it is best to change your vehicle’s DMF with the clutch. These two components work in synergy; hence they wear out simultaneously. However, one may wear out completely before the other.
The cost of replacing a vehicle’s clutch usually covers the replacement of the dual mass flywheel. In that case, changing the DMF along with the clutch will help you cut costs, especially if the component has reached around 80,000 to 90,000 miles.
Q: Can you replace a DMF with a normal flywheel?
Yes, it is possible to replace a DMF with a normal flywheel. However, it will alter the normal operations of the vehicle and the driving dynamics. The vehicle will require more gas, and the gear-shifting will become entirely different.
Another experience you will have to bear when you switch from a DMF to a normal flywheel is the vibration, noise, and harshness. This can really be disturbing if you’re not used to the discomfort that comes with these effects.
So, if you want a replacement for your vehicle’s DMF, kindly get another DMF that is suitable for the replacement. This will help you retain your peace of mind.
Q: What is the most common cause of dual mass failure?
The most common cause of dual mass flywheel failure is excessive heat. This is usually due to a slipping clutch. A vehicle with a slipping clutch will always generate excess heat, which can affect the DMF and cause it to fail.
One simple sign of a failing dual mass flywheel is the banging or rattling sound that comes from the bell-housing.
If you’re experiencing this symptom already, kindly replace the DMF. On the other hand, if you have a worn-out clutch, ensure to replace the component before it damages the DMF.
Q: How expensive is it to replace a flywheel?
Replacing a flywheel costs around $600 – $1,100. However, the cost of replacement depends on the vehicle’s make and model. While some are relatively cheap, others can be very expensive. Also, the labor cost is another factor to consider.
If you’re an expert mechanic, fixing your new DMF may not be an issue. This can also help you cut the costs to an extent. Also, having a family or a friend who is a professional auto mechanic will be helpful at this point.
Otherwise, you may have to spend a couple of bucks fixing the component. However, replacing a defective flywheel is worth it because the bad dual mass flywheel symptoms in Vauxhall or other cars are really frustrating.
Q: What cars have dual-mass flywheels?
The list of cars with dual-mass flywheels includes Ford Focus, Acura TL, Nissan Altima, and Hyundai Sonata. These cars perform excellently well with the dual mass flywheels.
The component does not produce any harshness, noise, or vibrations when the vehicles are running.
However, the component can be frustrating once it becomes defective. As a matter of fact, Ford Focus dual mass flywheel symptoms are not different from VW Golf dual mass flywheel symptoms.
The cost of replacing the DMF is pretty high compared to the replacement cost of a single-piece flywheel. So, if you drive any of those cars listed above, ensure to maintain a good driving style and a regular maintenance culture.
Remember that dual-mass flywheels are usually at the mercy of the car owner’s driving style. So, if you want the component to last long, you better keep this caution at your fingertip.
Final Words
Dual mass flywheel symptoms are very obvious to the point that they are hardly unnoticed. If you fail to notice the signs of the defection in the component, you may be running a risk of damaging other parts of your vehicle in the long run.
However, if you suspect that your vehicle’s DMF is faulty, kindly take some time to inspect and diagnose it to find out what could be wrong.