FULL VERSION SPARK CVT DOCUMENT

SMALL OVERVIEW ON HOW THE SPARK CVT7 WORKS, IS MAINTAINED AND FAILS

FULL VERSION:

First off I would like to thank a user on reddit whos account is unfortunately deleted. They “sparked” (pun intended) my interest in this transmission and inspired me to make a post like theirs. They are a saint to this little niche community and I seriously appreciate their informative posts. Here is a link to their post.

All about your CVT: What it is, why its unique and how it works:

CVT stands for “Continuously variable Transmission”. Instead of having set stepped gear ratios like a “regular” automatic transmission does, a CVT has a continuously variable amount of gear ratios. A CVT is belt and pulley driven, which allows for a smooth change between the relatively infinite amount of gear ratio. Because there are no set gear ratios like a “regular” automatic, the term “stepless” is used to describe CVTs.

If you have driven a car with a regular automatic transmission you have likely felt the jolt when the gear shifts up and down. This is NOT supposed to be present when driving a CVT.. however, consumers didn't like not having that shifting jolt feel, so simulated shifts were added to CVTs.

Here is a video on how a “regular” automatic transmission works

Here and Here is a few videos demonstrating how a CVT works, this may NOT be identical to the JATCO CVT7 (JF015e) in the Spark.

Here is a webpage about CVTs

Why are people scared of/ hate CVTs?:

Before anyone comments.. Yes I am a filthy CVT transmission sympathizer. I think they are neat, have potential and should be reconsidered. For folks unaware, here are a few main reasons folks hate these transmissions:

Reliability- When CVTs were first widely implemented in cars, they were not great.. Folks were also really put off by Nissan CVTs being problematic and failing at low mileage. Nissan has been sued over their CVT transmissions failing super early and unfortunately the spark shares the same CVT that is at the center of the lawsuit.. We will cover how the stigma of CVT transmissions, while overblown…is not totally wrong.

Repairs and Remanufactures- Chances are, if you ask your dealership about your CVT problem, they will tell you that it cannot be rebuilt or repaired and it is easier to just replace the entire transmission… We will touch more on this later, but most people are scared of the cost to repair/replace and shops probably don't want to mess with them. This is either due to lack of training, knowledge, patience, or honestly resources, but it varies depending on where you live.

ThEy ArE sLoW- I do not have the time or patience to unpack this… they are put in economy cars for economy reasons. They are usually not able to handle ridiculous amounts of power, so yes, they are usually in slower vehicles with smaller motors. However, they are not the loser transmission everyone says they are..the rich history of CVTs and racing is interesting to read about and I have included some articles below

Here is a little trivial information about CVTs in F1 racing

Here is an article about the CVT power limitations

What is so special about the Spark’s CVT?:

The JATCO CVT7 (commonly known as the JF015e/ RE0F11A ) is not truly a stepless CVT because it has an auxiliary gearbox attached! When driving your spark you may feel it jolt or “shift” around around 8- 18 mph, this is the “lockup torque converter clutch” and not a real “shift”. At 18-30mph, this is a REAL shift from the auxiliary gearbox to the CVT belt and pulley mechanism.

The CVT7 is also infamous for how particular it is about its CVT fluid. This transmission relies on the fluid for almost every job it is supposed to do, so when that fluid is not perfectly clean and new, it can cause performance issues and mechanical problems.

Here is a video that demonstrates how this variant works

How does my CVT work? (The watered down basics (kind of):

Here is another video that may help visually show the operation of a CVT

The belt and pulley mechanism on your CVT is composed of the Steel Belt, the Primary (Input) pulley and the Secondary (Output) pulley.

Both pulleys are operated by oil pressure and consist of a shaft with a non movable slope (aka fixed cone surface), a movable sheave, and an oil pressure chamber on the back of the movable sheave.

This CVT has what is called a “Push V-Belt”, This Steel Belt is composed of two steel rings holding several hundred steel plates together (like a chain almost).

Using various input signals such as Engine load, engine RPM and vehicle speed, oil pressure will be applied to the primary and secondary pulley. When there is oil pressure applied, the moveable sheave will slide on the shaft to change the groove width of the pulleys. This change in groove width will cause the belt to “walk” up and down the two cones and change gear ratio. Because this CVT uses a “push belt” friction force is needed to generate power, think of it like the cones are pushing against the belt and the belt pushes back against them. When the transmission slips, the friction is briefly lost and the belt cannot “grip” against the cones.

Here is a video that demonstrates groove width change better (1:04-1:18)

Oil Pressure System

The oil pressure is generated by a chain driven oil pump.This It is then pushed through multiple routings and fluid lines.

Various other electronics, sensors, solenoids and valves are present inside the valve body that are responsible for routing the transmissions oil, applying brakes and clutches, etc.

So basically….:

Engine power transfers through the torque converter >The power from the torque converter is then transmitted to the primary pulley through the counter drive gear and the counter driven gear. >This moves the pulley sheaves along the shaft to change the groove width> This makes the steel belt “walk” up and down the pulleys> Which changes the gear ratio

The mastermind behind almost all of the transmissions work is the Transmission Control Module (TCM). Using various inputs from other components, sensors, and driver input: The TCM will activate various solenoid valves and control the shift of the transmission. As explained in the Nissan Versa Transmission and Transaxle manual I found on the NicoClub website: “To select the gear ratio that can give the driving force to meet driver's intent or vehicle situation, the vehicle driving condition such as vehicle speed or accelerator pedal position is detected and the most appropriate gear ratio is selected and the shifting method before reaching the speed is determined. The information is output to the primary pressure solenoid valve to control the line pressure input/output to the primary pulley, to determine the primary pulley (movable pulley) position and to control the gear position.” Alongside this description there is also a chart provided:

IN THIS DOCUMENT I WILL NOT BE COVERING TCM TUNING OR MAPPING, IT IS MORE IN DEPTH AND IMPORTANT SO DO YOUR OWN RESEARCH IF YOURE CURIOUS!

The reduction gearset transmits power from the transmission section to the final drive.

The Auxilary Gearbox is attached to the Secondary (output pulley) and is composed of a planetary gearset, multi disc clutch, multi disc brake, etc. I do not feel like going super indept on how this component works, I apolgize. Hopeuflly the sources provided at the bottom will better help you understand if you wish to do some research.

Here is a link to a video that may help explain this a bit better

Additionally, here is a video that disassembles this CVT with helpful commentary on which part does what

The cooling system:

The CVT cooling system in your Spark is set up a little different than the ones found on Nissan and Mitsubishi cars. Your CVT fluid needs to be cooled to prevent overheating and to maintain smooth operation. To do this, General Motors engineers (or whoever designed this) ran lines from the CVT to the CVT innercooler inside the radiator.

Picture of nissan heat exchanger: this component allows the CVT fluid to heat up quicker to its operating temperature as well as act as a cooler. This component has its own thermostat device that will “open” and “Close” when the TCM commands it. The spark does not have this feature that I am aware of.

I need to locate my source for this, I may have to call a dealership to confirm my source but I was told that the reason it is located inside the radiator is so the coolant helps warm up the CVT fluid and then cool it down when it’s overheating.

The “TOO COLD” temperature for your sparks CVT is anything under 68F.
The OPERATING temperature for your sparks CVT is ~120°F to ~176°F
The OVERHEATING temperature for the CVT is 190-200°F
The average temperature I have seen for the Engine Coolant is 180-210F. This is important to keep in mind because the Sparks CVT “cooling system” runs through the inside of the radiator which can cause overheating.

The cooling setup for your CVT works in theory, but if anything is wrong with your cooling system or your coolant is over 180°F, it overheats the CVT. Furthermore, the spark does NOT have any temperature gauge…so you can’t see if anything is overheating until the warning light comes on, which is too late in most cases. It is possible to “swap” the Nissan heat exchanger onto the spark and/or install an aftermarket inner cooler (that is what I did)

All about your CVT fluid, inspecting magnets, service interval, flushing, and how to better take care of your transmission:

The fluid inside of your CVT is extremely important because it provides lubrication to parts, cools things down, and is responsible for hydraulic pressure. The fluid may also be called oil because of its lubricant properties. It has detergents, frictional modifiers and viscosity index improvers. The detergents are responsible for cleaning off the internal components while the frictional mofifiers provide enough grip for the steel belt and other components relying on friction force. The viscosity index improvers make the fluid thicker while cold, and thinner while warm. CVT fluid has an ideal operating temperature and the fluid should remain in this interval. if too cold, the thicker fluid will cause more work to be done which results in wear. On the other hand, the fluid getting too warm also causes wear due to overheating the unit. It is important to use CVT fluid specific to your transmission because there are different “recipes” that are better for different kinds of CVTs. While I dont want to debate about which brand is better, you can never go wrong with using the manufacturer recommended fluid. However, I will say that you DO NOT use ATF/”Automatic transmission fluid” (such as Dexron-VI) or any “multi-purpose” fluid in your CVT. This is because at the most basic level a regular automatic transmission and a CVT need very different characteristics in their fluid. While it may be possible to have a multipurpose fluid that works, it isnt going to work for long at all, and can cause more damage than you would want to pay for. The manufacturer recommended CVT Fluid (ACDELCO #19260800 10-4092) is a green almost aqua blue color that is translucent. It has a strong smell and is a little difficult to find sometimes, so DIY folks buy in bulk usually.

There is some confusion when it comes to the fluid change service interval for your Spark… which how could there not be when everyone is telling you different answers. I will not go into the problem of dealerships lying about changing the fluid in this post, but know that your owners manual has “45,000 miles” listed as the official interval for “severe'' use. So…Lets get a few things straight:

You MUST change your CVT fluid. No exceptions. There is no “sealed system” on this transmission that prevents you from changing the fluid and the fluid does NOT last the “Lifetime” of the vehicle.
You need to change both filters when your fluid is changed (unless they are magically spotless for some reason) and INSPECT your fluid pan magnets. (these magnets will also need to be replaced eventually, its up to you to decide when that is done)

“Severe” use applies to most people.
You cannot put ATF, Multipurpose, or anything in your transmission EXCEPT CVT FLUID. I will not discuss what brand is best in this post…that is up to you to decide, but you can never go wrong with the OEM fluid.

Inspecting your Magnets:

When the fluid is drained from your transmission and you remove the drain pan to replace the bottom filter/strainer you should inspect the two magnets located on the bottom of your fluid pan. You may notice some sludge buildup on these magnets, depending on what that sludge or debris looks like, you may need to brace yourself for repairs to your transmission.

Below is a set of images of debris that is ACCEPTABLE to see on your magnets:

This debris is minimal, and does NOT have any metal chips within it. Using a rubber/latex glove run your finger through this sludge to clean off the magnets and rub the sludge between your fingers. IF you do not feel any grit or particles, all is well. This means business as usual within your transmission and you should proceed with a fluid change, filter change, possible flush, and possible magnet change if needed.

Below is a set of images of debris that is NOT ACCEPTABLE to see on your magnets:

This debris is clearly abnormal, and may metal chips within it. Using a rubber/latex glove run your finger through this sludge to clean off the magnets and rub the sludge between your fingers. IF you do feel any grit or particles, there IS an issue present. This means something is failing inside the transmission, probably the belt has been chipping or a variety of other components are being damaged. Depending on what you find and how much is present you may proceed with a fluid change, filter change, possible flush, and possible magnet change if needed. However, it is best to take pictures and make note of ANY abnormalities you feel/hear/see/smell while driving your spark…and you should schedule a visit to a trusted shop.

So what is the actual fluid change interval?:

The first fluid change of a new/Rebuilt/Remanufactured CVT should be at 10,000-15,000 miles.

The regular fluid change interval should be every 18,000 to 25,000 miles.*

This interval can vary depending on how you drive your Spark. The following conditions would shorten the interval between fluid changes:

Repeated short trips of 5 miles or less in normal temperatures.
Repeated short trips of 10 miles or less in freezing temperatures.
Stop and go traffic in hot weather.
Low speed driving for long distances
Driving at high speeds
Driving in hilly or mountain-like terrain
Harsh and sudden acceleration
Driving in muddy, dusty, or salty conditions
Towing or driving while loaded down (this can potentially include passengers)

These conditions would shorten the interval because they cause debris and excessive wear on your transmission. It is a good rule of thumb to remember that heat will break down your transmission fluid and cause excessive work to be done by your car. Your CVT uses friction to operate, and that creates a lot of heat…so while it may seem like this is a very frequent service interval, remember that some machines need more maintece than other… and unfortunately your transmission happens to be one of them.

I was told by a GM technician that also worked at Nissan (who is the primary user of these CVTs) that in hot weather these CVT will “throw fits” for several reasons. This includes a failsafe mode that restricts gear ratio, hesitation, lagging, and bucking along with other problems that can damage the CVT and be dangerous in traffic…So if it is hot outside (above 90-95F) and you have encountered these “fits” before, remember that the car may act up again.

If your transmission begins to throw a fit, consider stopping the vehicle for a while to let it cool down. I can't say for certain how exactly you can exit all of the failsafe modes for the CVT, but i do know that sometimes turning it off and sitting for a few minutes may help.

*You could wait until 25,000-30,000 miles if you feel/hear/see no issues with the transmission, but that is solely your decision. While this may seem like a short interval, this is the ideal mileage to prevent any damage from occurring. Sure, some people go 45,000 miles with no issue, but they are lucky or they baby their car. CVT Fluid is not cheap, trust me it sucks to buy, but think of it this way “$200 every other couple of months/year, etc., or $6,000 for a new transmission”.

Flushing Your Transmission:

I am not going to get into the debate about flushing your transmission on this post. However, a CVT is very different from a regular automatic transmission. CVT fluid will have debris and must be clean in order to operate- that is a fact. It is highly recommended to flush your transmission to remove this debris and prevent issues that we will discuss in the next section- however the fear of your transmission failing after this is done is somewhat of a myth. If your transmission fails after a flush, there was already an issue to begin with.

Have low miles? Flush it. It is needed. You may be able to get away with the fluid change using 12qts of fluid and cycling it through or whatever unless you have a ton of debris in the pan.
Have high miles and barely had a fluid change if ever? You should get a flush service done by a trained technician. That is your choice to make, but as we will discuss later, it is important to prevent a ton of damage. During professional fluid changes, the service manual for Chevrolet shows a special machine is used to flush the fluid and test the pressure in the lines.

It is important to note that damage can be done if the CVT is flushed improperly. It takes a special machine and or a trained tech to do a real flush. Sure you can cycle fluid through several times but it will not be as effective as a pressurized flush service.

Damage can also be done if the fluid is changed without changing the filter or a flush is performed with unchanged/dirty filters as the debris inside the filter most likely will fall out of the filter and circulate throughout the transmission and cause several issues along with permanent damage and even catastrophic failure. (This is what killed off my second transmission since the dealership refused to replace the filters… within a week my CVT was gone)

How to better care for your CVT transmission:

Change your fluid every 18-25,000 miles. (If you have NO problems, drive with care and nothing is out of the ordinary, you can wait to change your fluid, that is your choice. I drive my car very rough and in an extremely hot and humid environment, so I choose to change the fluid way sooner just in case.)
Check the condition of your fluid every 6 months and if you drive it frequently, it is a good idea to do a yearly pan magnet inspection and even fluid change. However, this is up to your discretion.

—>alternatively, run the car till the CVT is at operating temp and then remove the drain plug and see what comes out (this is to check the fill level). You can pour in a quart of a cup or so into the fill tube and catch any overflow in a jar to inspect the fluid without all the pan dropping work. Be sure to let the fluid stop dripping a ton before reinstalling the plug to prevent overfill! Be sure to have the transmission up to operating temp and on a level surface as the fluid may pour out of it if not level and warmed up.

Let your CVT warm up when it is cold outside! Yes, I know modern engines do not need to be warmed up.. Blah blah… but this CVT DOES. At least let it warm up for a few minutes before driving the car. If you live in an extremely cold environment consider putting cardboard In front of the radiatior or something else that may help speed up the heating process. If you are in a very very cold environment and do not heat up your CVT to a certain temperature it can actually refuse to drive over certain speeds and it can cause damage to components.

If you do not have time to let it warm up, then drive slowly and gently (I don mean staying at 10mph, but don't just gas it and get up to 75mph as fast as you can) for about 5-10 minutes or so.

Why? Because the contaminants in the fluid can cause more wear and the components inside the transmission can wear out quicker when cold. If you ignore warming up the transmission when it is cold outside and you gas it in a rush, you may feel the belt slipping and there could be a noise, shudder, hesitation and or lag. This is something that can happen at any temperature.

Do not slam on your gas pedal to take off from stops, I understand if you need to get going fast, but you will do better for your transmission and getting up to speed quicker if you ease onto the pedal and find the “sweet spot”. It is worth experimenting with and testing out to see what works best for your car. The CVT is programmed to sometimes have a fake shift if you step on it, even just kind of stepping on it too quick, which is what can create a large lag. It can be annoying, but you can actually bypass this if you find the right amount of pushing the gas pedal.
Try not to constantly go over 85mph all the time. I know…I know.. Some of us have a need for speed, but there is a few components in your transmission that are NOT cooled by the fluid and can overheat if you go that fast constantly. Likewise, the vibration at that speed can also cause some damage. I dont feel like discussing this component in this post, but will in a later one.

Why do these transmissions fail so much?

The biggest contributor to these transmissions failing has to do with the fluid. There are several moving parts in your transmission, (I will have a separate tear down post and hopefully video for more in depth looks at the CVT7 and it's components. ) that need to be cooled and lubricated. As we previously covered, the fluid is vital and if it is dirty or contaminated it will fail. While sudden complete failure is usually rare, it is not impossible. More commonly, the driver may not notice the signs of upcoming CVT failure.…However, in this post I will talk about the main issue of dirty fluid and the process of how the issues develop into a complete failure of your transmission.

Wear of the valve body can lead to fluctuations in oil pressure. This CVT uses oil pressure to preform most tasks, so when this pressure fluctuates it will cause the pulleys and belt to move in unexpected and strange ways. This will cause a weird irregular motion while driving. (it may feel like your car speeds up and slows down rapidly.)

The valve body wear and oil pressure fluctuation can also lead to:

“shock” when you slow down and go into lower gear, as well as vibrations when you do go into lower gear.
Range Switching (it looks like your RPMs are going up and down a ton)
Reluctance to go into low gear while braking

This will require the valve body to be replaced, but they can be repaired if the issue is caught soon enough.

Irregular wear or seizure of the pressure relief valve. This is actually one of the main causes of early failures in this CVT. This specific issue can happen as early as 18,000 - 25,000 miles. This is why it is recommended to change fluid early for the first fluid change, so that you get rid of these initial contaiments before they clog the system.

Debris (specifically metal chips) can block up pressure controllers which further causes premature wear of valves.

Debris can actually clog up the chain driven oil pump, which becomes a big problem as it can no longer circulate oil properly.

Failure to change fluid or address any of these issues will result in the pulley-belt system becoming damaged. They will most likely need to be replaced (they are expensive) but they could be polished instead although it isn't guaranteed to fix it.

What is valve body wear exactly….? Well the simplest way to explain it is that the debris acts like sandpaper while traveling through the transmission (specifically in the valve body for this section). This debris can also clog up valves, solenoids, lines, etc. found in the valve body.

How is this debris formed? Well, the debris is formed when the transmission is operating… it's a catch 22 because this CVT (like any other component on a car) will eventually break and it is impossible to fully prevent that, but the trade off is great fuel economy. This CVT has debris formed from just driving, but the super harmful debris that speeds up the damage process is metal chips coming from the steel belt. When your transmission slips, that is mainly when the harmful debris is disbursed around in the fluid and through your system. Ideally the filters will catch this, but once they are at a certain filth point the debris will just circulate.

“The vehicle does not need an elaborate break-in. But it will perform better in the long run if you follow these guidelines: . Do not drive at any one constant speed, fast or slow, for the first 805 km (500 mi). Do not make full-throttle starts. (Flooring it from a full stop) Avoid downshifting to brake or slow the vehicle.”

Damage to the belt can actually be seen using a boroscope! Here is what you should look for when inspecting the belt:

This is new territory for me and I plan on making an in-depth tutorial/document on how to do this and not blow up your CVT.. so only do this if you have the know how or can afford a new CVT.

THE FOLLOWING ARE NOT GOOD TO SEE ON YOUR BELT:

TL;DR VERSION

How does my CVT work?:

This simple version is that your transmission uses a belt and pulley system to change gear ratio instead of gear stepping like a regular automatic transmission. What is special about your transmission tough, is that it ALSO has a gearbox attached to it, so it does have a stepped gear shift. This is usually felt at about 27Mph or when you step hard on the gas pedal because the transmission is programmed to fake a “real” shift when this occurs. This CVT also has a torque converted, which the lockup can be felt from 8-18mph, it is not a real shift.

Here is a video on how a “regular” automatic transmission works:

https://youtu.be/_6q5R2p8eHo?feature=shared

Here and here are videos demonstrating how a CVT works, this may NOT be identical to the JATCO CVT7 (JF015e) in the sparks

https://youtu.be/xHWqlfDZnmQ?feature=shared

https://youtu.be/PEq5_b4LWNY?feature=shared

Four important facts:

You MUST change your CVT fluid. No exceptions. There is no “sealed system” on this transmission that prevents you from changing the fluid and the fluid does NOT last the “Lifetime” of the vehicle.
You need to change both filters when your fluid is changed (unless they are magically spotless for some reason) and INSPECT your fluid pan magnets. (these magnets will also need to be replaced eventually, its up to you to decide when that is done)

“Severe” use applies to most people.
You cannot put ATF, Multipurpose, or anything in your transmission EXCEPT CVT FLUID. I will not discuss what brand is best in this post…that is up to you to decide, but you can never go wrong with the OEM fluid.

CVT Fluid operating temp and extreme temperatures:

The “TOO COLD” temperature for your sparks CVT is anything under 68F.
The OPERATING temperature for your sparks CVT is ~120°F to ~176°F
The OVERHEATING temperature for the CVT is 190-200°F
The average temperature I have seen for the Engine Coolant is 180-210F. This is important to keep in mind because the Sparks CVT “cooling system” runs through the inside of the radiator which can cause overheating.

What fluid does my Spark’s CVT use?:

The fluid inside of your CVT is extremely important because it provides lubrication to parts, cools things down, and is responsible for hydraulic pressure. CVT fluid has an ideal operating temperature and the fluid should remain in this interval. If too cold, the thicker fluid will cause more work to be done which results in wear. On the other hand, the fluid getting too warm also causes wear due to overheating the unit. It is important to use CVT fluid specific to your transmission because there are different “recipes” that are better for different kinds of CVTs. While I dont want to debate about which brand is better, you can never go wrong with using the manufacturer recommended fluid. However, I will say that you DO NOT use ATF/”Automatic transmission fluid” (such as Dexron-VI) or any “multi-purpose” fluid in your CVT. The manufacturer recommended CVT Fluid (ACDELCO #19260800 10-4092) is a green almost aqua blue color that is translucent. It has a strong smell and is a little difficult to find sometimes, so DIY folks buy in bulk usually.

When should I change my CVT fluid?:

The first fluid change of a new/Rebuilt/Remanufactured CVT should be at 10,000-15,000 miles.

The regular fluid change interval should be every 18,000 to 25,000 miles.*

This interval can vary depending on how you drive your Spark and if it is performing well or not. The following conditions would shorten the interval between fluid changes:

Repeated short trips of 5 miles or less in normal temperatures.
Repeated short trips of 10 miles or less in freezing temperatures.
Stop and go traffic in hot weather.
Low speed driving for long distances
Driving at high speeds
Driving in hilly or mountain-like terrain
Harsh and sudden acceleration
Driving in muddy, dusty, or salty conditions
Towing or driving while loaded down (this can potentially include passengers)

I was told by a GM technician that also worked at Nissan (who is the primary user of these CVTs) that in hot weather these CVT will “throw fits” for several reasons. This includes a failsafe mode that restricts gear ratio, hesitation, lagging, and bucking along with other problems that can indicate damage to the CVT and be dangerous in traffic…So if it is hot outside (above 90-95F) be mindful of the issues that could come from your transmission.

*You could wait until 25,000-30,000 miles if you feel/hear/see no issues with the transmission, but that is solely your decision. While this may seem like a short interval, this is the ideal mileage to prevent any damage from occurring. Sure, some people go 45,000 miles with no issue, but they are lucky. CVT Fluid is not cheap, trust me it sucks to buy, but think of it this way “$200 every other couple of months or $6,000 for a new transmission”.

How do you inspect your magnets?:

Below is a set of images of debris that is ACCEPTABLE to see on your magnets:

Below is a set of images of debris that is NOT ACCEPTABLE to see on your magnets:

Flushing your CVT:

I am not going to get into the debate about flushing your transmission on this post. However, a CVT is very different from a regular automatic transmission. A CVT’s fluid will have debris and must be clean in order to operate correctly- that is a fact. While It is highly recommended to flush your transmission in order to remove this debris and prevent issues that we will discuss in another section- There is a looming fear of the flushing your CVT leading to it breaking…This fear of your transmission failing after ta flush is somewhat of a myth. If your transmission fails after a flush, there was already an issue to begin with.

Have low miles? Flush it. It is needed.
Have high miles and barely had a fluid change if ever? That is your choice to make. (Personally, I would flush it)

How to care for and maintain your CVT:

Change your fluid every 18-25,000 miles. (If you have NO problems, drive with care and nothing is out of the ordinary, you can wait to change your fluid, that is your choice.)
Check the condition of your fluid every 6 months and if you drive it frequently, it is a good idea to do a yearly pan magnet inspection and even fluid change.

Let your CVT warm up when it is cold outside! Yes, I know modern engines do not need to be warmed up.. Blah blah… but this CVT DOES. At least let it warm up for a few minutes before driving the car.

If you do not have time to let it warm up, then drive slowly and gently (I don't mean staying at 10mph, but don't just gas it and get up to 75mph as fast as you can) for about 5-10 minutes or so.

Why? Because the contaminants in the fluid can cause more debric and the components inside the transmission can wear out quicker when cold. If you ignore warming up the transmission when it is cold outside and you gas it in a rush, you may feel the belt slipping and there could be a noise, shudder, hesitation and or lag. This is something that can happen at any temperature, but it is primarily felt when cold.

Do not slam on your gas pedal to take off from stops, I understand if you need to get going fast, but you will do better for your transmission and getting up to speed quicker if you ease onto the pedal and find the “sweet spot”. It is worth experimenting with and testing out to see what works best for your car. The CVT is programmed to have a fake shift if you step on it even just kind of, which is what can create a large lag. It can be annoying, but you can actually bypass this if you find the right amount of pushing the gas pedal.
Try not to constantly go over 85mph all the time. I know…I know.. Some of us have a need for speed, but there is a few components in your transmission that are NOT cooled by the fluid and can overheat if you go that fast constantly. Likewise, the vibration at that speed can also cause some damage. I dont feel like discussing this component in this post, but will in a later one.

Why do these CVTs fail so often?:

The biggest contributor to these transmissions failing has to do with the fluid. There are several moving parts in your transmission, (I will have a separate tear down post and hopefully video for more in depth looks at the CVT7. ) that need to be cooled and lubricated. As we previously covered, the fluid is vital and if it is dirty or contaminated it will fail. While sudden complete failure is usually rare, it is not impossible…However, in this post I will talk about the main issue of dirty fluid and the process of how the issues develop into a complete failure of your transmission.

Wear of the valve body can lead to fluctuations in oil pressure. This CVT uses oil pressure to preform most tasks, so when this pressure fluctuates it will cause the pulleys and belt to move in unexpected and strange ways. This will cause a weird irregular motion while driving. (it may feel like your car speeds up and slows down rapidly.)

This valve body wear and oil pressure fluctuation can also lead to:

“shock” when you slow down and go into lower gear, as well as vibrations when you do go into lower gear.
Range Switching (it looks like your RPMs are going up and down a ton)
Reluctance to go into low gear while braking

(This will require the valve body to be replaced, but they can be repaired if the issue is caught soon enough.)

Irregular wear or seizure of the pressure relief valve. This is actually one of the main causes of early failures in this CVT. This specific issue can happen as early as 18,000 - 25,000 miles. This is why it is recommended to change fluid early for the first fluid change, so that you get rid of these initial contaiments before they clog the system.

Debris (specifically metal chips) can block up pressure controllers which further causes premature wear of valves.

Debris can actually clog up the chain driven oil pump, which becomes a big problem as it can no longer circulate oil properly.

Failure to change fluid or address any of these issues will result in the pulley-belt system becoming damaged. They will most likely need to be replaced (they are expensive) but they could be polished instead although it isn't guaranteed to fix it.

What is valve body wear exactly….? Well the simplest way to explain it is that the debris acts like sandpaper while traveling through the transmission This debris can also clog up important components found in the valve body.

How is this debris formed? Well, the debris is formed when the transmission is operating… it's a catch 22 because this CVT (like any other component on a car) will eventually break and it is impossible to fully prevent that. This CVT has debris formed from just driving, but the super harmful debris that speeds up the damage process is metal chips coming from the steel belt. When your transmission slips, that is mainly when the harmful debris is disbursed around in the fluid.

Some CVT fail within a few thousand miles of being put in a vehicle because there is a break in period for your transmission. During this break in period, fine metal particles and debris are dispersed in the transmission and end up clogging up a lot of things. I cannot find an exact number, but 500 miles is the consensus I could find for how long this period lasts. The owners manual also has this included: “The vehicle does not need an elaborate break-in. But it will perform better in the long run if you follow these guidelines: Do not drive at any one constant speed, fast or slow, for the first 805 km (500 mi). Do not make full-throttle starts. Avoid downshifting to brake or slow the vehicle.”’

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