The clutch is one of the most important parts of your quad’s transmission and despite this, it’s often overlooked by new riders. Today I will share with you everything you need to know about an ATV wet clutch to keep your four-wheeler running smoothly all the time.
Most ATVs have wet clutches because they are easy to use, last a longer time, are quieter, and can generally take a lot of abuse. In contrast to the dry clutch, a wet clutch is bathed in engine oil which lubricates the friction plates and keeps the clutch pack cooled for better durability. The only disadvantage of this system is that some of the power from the engine is conducted by the oil, meaning that you achieve higher speeds with a slight delay. This is the reason why dry clutches are preferred for racing, while wet clutches are the main choice for almost all motorcycles and ATVs seen on the streets.
Even though wet clutches are more durable, this does not mean that a cautious off-roader should not keep with its maintenance. Keep on reading to understand how your wet clutch works, what type of oil you need to use, and how to tell if your wet clutch is bad.
Do ATVS Have Wet Clutches?
Not all ATVs have wet clutches, but a vast majority have switched to this system because of its benefits. While some people might be big fans of the sound of a dry clutch like the well-known Ducati, the noise is actually the main reason why most manufacturers jumped ship.
The Noise Pollution Control Act and other similar laws outside of the US have pushed ATV and motorcycle brands to change their designs and abide by a fixed number of decibels. Therefore, manufacturers chose to use wet clutches and keep the satisfying roar of an engine instead.
Even though some ATVs have an automatic transmission and do not require you to use a clutch lever, these still have a sheave clutch as part of the CVT system. These work differently in order to maintain the optimal RPM at all times, but they can still be wet clutches.
What is a Wet Clutch on ATV?
A wet clutch is a type of clutch, one of the main elements of a transmission system. The clutch has the role of synchronizing the speed of the engine to the speed of the final drive in order to send power to the rear wheels.
The wet clutch has two clutch baskets that turn at their own speeds. Usually, the outer clutch basket connects to the engine and the inner clutch basket links to the final drive. When disengaged, these two will turn in tandem with the speed of their respective parts. In order to match their speeds, the clutch uses friction plates to connect the two.
As mentioned above, in automatic quads the clutch does all of this by itself. However, in manual ATVs you have a clutch lever, usually located on the left side of your handlebar. When you want to switch gears, you use this lever to disengage the clutch pack and allow the speed of the engine to increase or decrease, depending on the gear you are aiming for.
If you are new to four-wheelers and want to learn more about how they work, I highly recommend checking out this article I wrote about how ATV and UTV kill switches work.
When you press on the clutch lever, a part called the actuator moves to get out the push rod. This makes the pressure plate detach from the friction plates, which in turn makes your quad act as if it is in neutral. Once you release it, the speeds synchronize once again and your ATV can run smoothly in the gear you switched to. The working principle is the same for both dry and wet clutches, and is similar to switching gears in a car too.
If all of this mechanical talk seems a bit difficult to take in, I recommend you watch this YouTube video from a fellow off-roader that explains the process with a visual aid:
What Does a Wet Clutch Mean?
A wet clutch means that the friction plates of the clutch are bathed in engine oil for more efficient cooling. As a result, a wet clutch tends to last longer than a dry clutch, which is only cooled by the air outside the quad. At the same time, this means that the engine oil used with an ATV wet clutch becomes dirtier, requiring more frequent changes.
In my opinion, this is a fair trade-off to the advantages that wet clutches bring. For instance, this system has a wide engagement threshold. Riding on a quad with a wet clutch will feel smoother when shifting gears, while dry clutches can feel jerky at times, especially on hills.
How Do I Know If My Wet Clutch is Bad?
There are a few ways to figure out if your wet clutch is bad. The best way is to run regular maintenance checks on your ATV and open up the clutch cover to make sure the parts are still in good shape. The second one is to look for common bad clutch symptoms, such as slipping, dragging, creeping, and a burning smell.
The most common problem with a clutch is slipping between the pressure plate and friction plates. This happens because of wear and tear on the parts and causes the engine and final drive to not match up perfectly. The wheels will simply not match up with the engine’s RPM.
You will easily recognize this problem if your ATV accelerates way too slowly when switching into a higher gear. While wet clutches are more enduring, at some point this issue will happen to any ATV. The good news is that an ATV wet clutch only costs around 30-50 USD and you can change it quite effortlessly yourself.
It’s important to note that clutch slipping can also be caused by the wrong type of engine oil. Stay tuned for my tips on choosing the best one for an ATV wet clutch.
Another result of wear and tear on the wet clutch is damaged clutch baskets. When you have this problem, you will notice a difference in the way your lever feels while changing gears. If it doesn’t engage and disengage smoothly, then it is time to open up the clutch and check out the erosion on the clutch baskets.
Last but not least, another wet clutch issue that you can encounter is your friction plates burning off. The main telltale of this situation is quite literally a burning smell coming from the clutch pack. Sometimes the smell will be contained in the crankcase, but there is another symptom to look for: creeping.
If you are engaging the clutch lever and the quad still moves forward, then you are most likely experiencing this problem. Open up the clutch cover and look at your friction plates. You will see at least some burn marks and, in bad cases, even the entire plates coated in black residue. In this case, you will need to at least change the friction plates, if not the whole clutch all together.
What Oil is Safe for Wet Clutch?
The best oil for a wet clutch is engine oil formulated specifically for this type of system. That being said, the oils that are safe to use with a wet clutch are lubricants that do not contain any friction modifiers. While some people believe synthetic oil does not work that great with an ATV wet clutch, there is no definitive proof to show they cause more wear on the clutch parts.
Other mechanics might recommend not to use automotive oil either, but if it does not have friction modifiers it is still safe for the wet clutch. Friction modifiers have their own benefits such as increasing fuel economy, but they do not match well with wet clutches because they cause slipping. If you are set on using car oil, then go for Castor oil since it works better with an ATV wet clutch.
If you want to be on the safe side and help your clutch last as long as possible, my recommendation is to use an oil created with wet clutches in mind. You can look for engine oils marked with the JASO MA-1 or MA-2 classification. For automatic transmissions, it is generally accepted that you can use oils with some friction modifiers. These types of lubricants will have the JASO MB classification clearly displayed on the label.
Using the wrong oil is the most common reason for clutch problems aside from natural deterioration through time. My motto is always to be better safe than sorry. Check out this guide I wrote a few months back if you want a more in-depth guide to choosing the right motor oil for your ATV.
Do Wet Clutches Last Longer?
Compared to dry clutches, wet clutches last significantly longer. On average, if you use the right oil and maintain your ATV properly, you can easily go up to 60,000 miles without changing your wet clutch. Dry clutches on the other hand will last 30,000 miles at most. Still, seeing how they are often used for racing; the aggressive riding style will shorten that life expectancy drastically.
Heat is a major enemy to many ATV parts, so a system that keeps the clutch cooled properly was a revolutionary change in quad designs. And you, as the happy owner of a wet clutch four-wheeler, can reap the benefits by having one less part to worry about.
In most of my guides on components, I talk about how riding style and maintenance can make a world of difference in the state of your quad. With ATV wet clutches, it’s no different. There is definitely a huge difference in the durability of a wet clutch versus a dry clutch, but you need to take these factors into consideration as well.
The engine oil tends to get dirtier faster on a wet clutch ATV. Therefore, make sure to check your oil and change it once a month for the best outcome possible. This does not only protect your clutch, but the engine as well.
What are the Advantages of Dry Plate Clutch Over Wet Clutch?
A dry plate clutch has the advantage of not having fluid drag, unlike on a wet clutch. This provides more power to the rear wheels, resulting in quicker change in gears. Another benefit is that the oil does not get dirty as quickly, so it can save you some money on oil changes. Even so, wet clutches last longer and endure more abuse, making them the best transmission option in most cases.
I know I have been practically boasting about the benefits of a wet clutch, but I still have to give credit where credit is due. Dry clutches are the best option for racing competitions, where even one split moment can make the difference between a win and a loss. I love watching a good ATV race as much as the next guy, so I can appreciate that this clutch type gives the riders the necessary power to put on a good show.
Still, regular off-roaders like you and I will not even notice the difference in speed while on a trail. The loud noise of a dry clutch is fun at a race, but in everyday situations will likely become annoying in no time. Not to mention how much more frequent clutch changes are. Unless you are made of money, I would not switch to a dry clutch ATV just for an extra millisecond of power.
A wet clutch is a key component of the transmission system on most ATVs and motorcycles. It helps synchronize the speeds of your motor with your final drive seamlessly, providing a comfortable and enjoyable ride. Aside from that, it can save you a pretty buck in repairs if you maintain it properly. The best thing you can do for your clutch pack is to pick the right engine oil and change it regularly. If you just bought a second-hand ATV or you have an old quad, make sure to keep an eye out for a jerky clutch lever, slipping, creeping, and any burning smells.