Nissan CVT: Teardown and Failure Analysis -Part 2 (RERELEASE!)
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- Опубликовано: 26 авг 2024
- UPDATE: As of November 2019, the Nissan Rogue has 40k miles on the new CVT (225k total) and is running well!
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HAPPY NEW YEAR from PHAD!!
Since RUclips is disabling all paid content starting January 1, 2018, I have decided to rerelease the one and only paid video on my channel:
"Nissan CVT: Teardown and Failure Analysis -Part 2" ......
FOR FREEEEEEEEEEEEEE!!!!!!!
Thank you to those who supported the initial release of this video in June 2017, and I apologize for the messy comments section!
Maybe this time we can actually discuss the technical aspects of the CVT in the comments :)
***UPDATE December 2021:****
It has been 4 years and 60,000 miles since we replaced the blown CVT on the 2010 Nissan Rogue AWD. The car is currently running great, fingers crossed!
Please post your thoughts and technical questions in the comments below!
Ivan
I am a grandma of 6 and have wanted to learn more about CVT. You have done an excellent job of showing this old lady how it works. Joyce
You wouldn't be from Pasadena, would you? lol
Love, Jan & Dean
It's great to see a mechanic who is enthralled by the work he is doing. Ivan, you remind me of a man who lived over the road from me as a kid. He had an engine in his garage and asked 4 local kids if they wanted to take apart the engine. Of course we jumped at the opportunity. Anything we unbolted was thrown into a box. Anything we were stuck on he would come out and loosen for us. I learned later that he was a Senior Engineer at Dowty's. They were one of the top Aircraft parts manufacturers in the UK. He took this box of bits that we had amassed and rebuilt his engine. The sort of man who, if he didn't have the right tool for the job, would just make it. So watching you is rekindling childhood memories. I really enjoyed the teardown and brilliant explanation. Excellent video, thank you.
This is probably one of the best dissertations (via disassembly) of a CVT I've ever seen. Its really refreshing to hear the mechanic saying "really cool" instead "what's going on, that's stupid." There's hope, folks. I have a 2010 Nissan Sentra. Of course, its a less powerful powerplant and I've never tried to hot-rod or otherwise over-stress the car. I think the CVT is a sound concept for smaller cars. Now I have an idea of what's going on in my Sentra's CVT and how long it might last with normal driving. I'd still prefer a 5-speed stick though. Only need to worry after the clutch assembly ...
The fact that you cant find aftermarket rebuild kits for it (and in some cases at all), makes me hope it's retired for good. Keep it in lawnmowers.
this kind of transmission in working order seems like a miracle to me. It's like it's ready to break by design.
works great in motorcycles and really small cars, who thought to stick them in SUVs and vans I have no idea.
@@rnrbishop The French did
The clever thing is that the metal bands don't directly transmit the power,that is done by the segment plates pushing on each other.the metal belt is there to keep the segment plates aligned with each other.
Yup it's a "push" belt :)
Here's a great video that shows exactly how that works ruclips.net/video/PiwRUfFEc5k/видео.html
And there is rubber in the fluid, that's the actual friction material.
sceneitb4 quality! Raised a smile,they are called variators. Variable ratio sheaves., but pusheys sounds better!
@@andrewwilson8317 I could of sworn they are called element plates
Best CVT video on the internet...this cements my decision to avoid a Nissan CVT like the plague, and probably all others too
Thank you for the compliments!
Install a good cooler and keep the transmission fluid changed. There are many murano/rogue drivers in 200k range still running good with proper maintenance. Just like any other vehicle.
I've had my 09 Altima for 9 years I do regular maintenance daily. I'm over 225,000 miles and its still going strong. Wish you all luck and many ling miles with you all vehical.
Nissan could redesign the belts - the CVT works and works well, just update it with thicker belts made from stronger alloy.
Increase in cost and size and weight - but if it keeps the engine running it is more than worth it.
A 10 year warranty on the engine, drive train, and CVT would help too.
Maybe Nissan and Mitsubishi should consider using Aisin CVTs instead of Jatco CVTs.
You just convinced me never to buy a vehicle with a CVT transmission.
They are the most boring vehicle to drive haha
The Prius uses a planetary gear set with 2 electric motor/generators on it for torque and speed conversion. They don't rely on hydraulics, friction, or any mechanical shifting for operation other than the park pawl. It was the CVT I bought when I found out how they worked and that they were tested in city traffic in Japan for 5 years before the first ones came to the USA. I did not trust a snowmobile style transmission for a car daily driver.
@@ventureelect +1
Not all models, Toyota, and Mitsubishi technology are ok...
Mitsubishi vehicles also use a Jatco CVT but it isn’t the same CVT variant that Nissan equips in their vehicle. The big difference between a Mitsubishi CVT and Nissan’ CVT is their transmission control units.
I don't have a Nissan, but your presentation and process was very informative and fun to watch. 10 other people making this same video and it would have been dumb to watch. You made it worth my time! Thanks! I work in Electronics Engineering, but working for my dad as an auto mechanic many years ago during my college days both paid for school and was an invaluable mechanical education that has paid its way many times over since then. I think I could still rebuild a 2 barrel Ford carburetor with my eyes closed. :)
Thank you Thom, your comment really made my day! Experience in a variety of fields is priceless. I try to learn something new every day :)
Those chipped up 'ball bits' in the variator are cobalt steel locator ball bearings, and you are right in saying these balls are to lock the variator together with the shaft. Since they were wearing such deep grooves in the shaft relief the assembly shifted out of alignment and thus the variator could not change ratios as needed. It likely caused the belt to be super stretched while being pulled apart during ratio adjustments and the belt just snapped. The blown out seal was from high oil pressure feeding into cavity at such a high pressure (800+ psi) that when the variator assembly could no longer change ratio the pressure spiked and just blew apart the seal gasket.
Not sure why a spline design wouldn't be the better option? Your thoughts?
Sounds like a plan ...
Those CVT transmissions are like engines with rubber timing belts that cannot be changed without a complete disassembly. The carmakers should be forced to make those belts replacable as a maintenance item before they break like the timing belts.
Wouldn't have worked in this failure, the drive pulley failed first.
that was thier promise when these turds were first debut, easy to fix,,,, bullshit.,!
@@marcusmarcus8616 look at this statists bootlicker.
@@quattro4468 What are you talking about?
NO...You can replace the CVT belts until you are blue in the face. This type of failure has nothing to do with the belt... It's the pulley system shaft that failed. Once that shaft gets jammed in place.. The poor belt is at the mercy of forces it was not designed to handle.
I have a 87 Pathfinder with well over 200,000 miles and still going. My sister bought it new, then gave it to me several years ago when she got a new car. A friend has a 92 Maxima with over 350,000 miles and still drives it daily. Neither has had any motor or transmission or really any other issues.Based on their reliability, I got a 2005 Murano SE that was $40,000 new, thinking I'd get 25-30 years out of it. Well as of July 2017, after 12 years, 220,000 miles and two failed CVT's, oh and a phone book thick folder of replacement parts receipts, I quit.
My son works at a large car dealership. He said that if a customer comes in with a Nissan with a CVT for trade, they give them a ridiculous low trade in offer because they cant get rid of the used ones they have. He said the words out. If you mention to a customer Nissan with a CVT you might as well said it was a Yugo. I have friends, co workers, family members who all drive just about every brand that's out there, foreign and domestic. The consensus is that most all modern vehicles are made to be disposable. Yes they have better styling now and lots of neat features, but the overall quality sux.
I think you are the only one to have made a video showing so much details about the innards of those CVT. Very informative and it was a pleasure to watch both episodes.
I have a CVT transmission in my 2015 Subaru Outback. I have had my car for three and half years. I didn’t know anything about CVT. However after seeing your video I will pay attention to my transmission. I want to thank you for your in-depth breakdown of the transmission. I have subscribed to your videos and hope to watch all of yours in the future. Thank again for all your work.
Cheers,
John
Nissan engineers: how long should our cvt last? Management: at least 36000 miles. We don’t want it to die under warranty
wall it did last 180k miles
@@joshuamcpeek4708 one wonders if it's fluid changes were performed at the recommended intervals. I do find it a bit of a :-) when I read all the angst about oil change intervals people cutting oil filters in half people complaining about how oil filters are manufactured blah blah blah but will think nothing of running their transmission fluid changes to beyond the recommended time length let alone replacing it early.
@@stevewhite3424 yeah most of the time manufacturers try to feed you the lifetime trans fluid bs. Where there's no trans fluid pan drain and sometimes no trans fluid dip stick either.
@@joshuamcpeek4708 My wife had a 2011 Subaru Outback with a CVT, I asked Subaru Dealer in Newton NJ to change the CVT fluid, they said lifetime fluid, I said but shouldnt you change it. They said no it causes problems...... Huh? (turned head to side like puppy hearing strange sound)
@@johnlang2293 sometimes it can but it really depends on milage, like if the car has 165+ miles changing the trans fluid is actually not a good idea the fine metal shavings help provide grip between the worn clutch plates in auto transmissions and transfer cases so if you remove the fine metal grain from the fluid the worn out plates could slip.
This guy is a genius. I'm learning so much from this explanation of the CVT. Please keep other videos like this!
Thanks for the teardown and failure analysis.
I believe that that those "nuggets" were ball bearings at one time, to guide the hydraulic piston up and down, while acting as keys.
Knowledge is power! Thank you for taking your time to educate the masses.
you turned a DIY mechanic job into a science fair with a lesson... LoL I LOVE YOUR VIDS!!!
The pulleys aren't "coaxial", they're coplanar. In the same plane. Love the teardown. Appreciate you risking the core charge.
2000 Nissan Rogue Transmission making a humming noise it only makes noise when you put it in Drive
Amazing tear down and diagnosis! I bought a Murano completely unaware of the CVT flaw. Although I am not a mechanic of any description, I feel I now have a good understanding of how CVT's work and the potential problems after viewing this very informative video. Cheers!
So, if you buy a vehicle with a CVT transmission be sure to get one with big balls.
Something to make up for the small brain that bought one of Nissan’s.
if you buy CVT lease it, buy new, or buy aftermarket warranty for it. I bought my Maxima brand new and its pretty ballsy for a CVT fwd car. no sluggish rubber-band feel to it at all. even acts like a traditional auto under heavy acceleration to reduce premature wear due to sliding during ratio change under heavy torque. it pauses engine input for a fraction of a second while it changes ratio really quick so there is less stress on the belt when its moving on the pulleys. if it blows up, I get a new trans. following the fanbase, the new CVT in the 8th gens seem to be holding up much better than previous generations.
I sure as hell wouldnt buy one over 60K miles though without getting aftermarket powertrain warranty though.
Zac Price I bought a 2016 accord with a 2.4L and cvt trans, bought it brand new from the dealer with a lifetime drivetrain warranty so long as I follow their maintenance plan which is really no big deal because I’m a technician at a shop so it’s super cheap for me to do maintenance, so far I’ve got 25k on the car and have absolutely no complaints about the car or the cvt it drives super smooth and is actually fairly quick for a 2.4
@@2491kridge So the Lifetime Warranty is legit as most dealers say it is? I was looking at slightly used Toyotas and like the Corolla. Meh long as I have the CVT serviced at the dealer every 2-3 years (I drive mostly short stop and go trips), I got proof when it comes to claims.
MrCliffda3rd I mean I haven’t had to make any claims yet but yes some dealerships offer lifetime drivetrain warranty, the warranty doesn’t come from the manufacturer it comes from the specific dealership you buy from and the way they try to get you is making the maintenance plan that you precisely have to follow cause they want you to do all your service with them cause you’re scared you’ll loose your warranty but as long as you follow their plan correctly you can do the maintenance wherever you want
You are correct, the failure was the primary pulley seizing up. This caused the belt to fail not because of off center loading but by stretching and snapping it. Both pulleys are one way hydraulic systems so they both can close up with hydraulic pressure and the constant tug on the belt while in motion forces the pulleys to spread open. The primary pulley was jammed closed with hydraulic pressure forcing the belt to the outer edge. When the secondary pulley was told to close up during acceleration the primary pulley would not open up and snap goes the belt. Now I could be wrong but at least it's food for thought.
Yup sounds like a plausible theory!
It's amazing these engineering marvels even work as well as they do (when they do of course). The crazy thing is the failure in this transmission could easily be made more robust and these transmissions could probably last twice as long! But then again what car manufacturer wants anything to last that long anyways?Your teardown and failure analysis videos are among the best on RUclips and I thoroughly enjoy each and every single one. Like you, my mind needs answers! Why did it fail, how did it fail and is there anything I can do in the future to prevent the same failure. Keep up the great work!
SAMP, Not sure your fully right about "constant tug" comment. I believe the belt works in compression(segments pushed together) and not in tension(tugging or pulling on the belt) The steel bands could have broken in a bending force during high engine torque and a numerically low gear ratio event. Same end result but a little different failure mechanism, just another thought.
186 thousand miles is a pretty dang good life for any transmission, thanks for the breakdown.
I have a 2005 Altima with 350,000 miles. I use synthetic and Lucas. Proof that fluid changes prolong life, still driving to my goal of 400,000 miles!!
I am not technical, and certainly not an engineer. But even I could see that this design was too light to last. It is a miracle it lasted as long as it did. I drive a Jatco CVT too (but the lightest version for very small engines). I hope for the best. But... that being said, I knew the reputation of Jatco and still bought it. Just wanted to know how a CVT drives. I like it. Just do not be in a hurry.
Not even half way through yet, but i would think that the belt would normally be a reliable part of the cvt, i say that because when the pulleys are operating correctly in unison there is not sudden jarring or uptake of drive when shifting ratios - unlike a normal transmission where wear of clutch packs and such can cause a sudden snatch when gears are shifted, causing a sudden high torque load on a normal chain. So i am thinking one of those pulleys misbehaved causing the belt to break. But, whatever the cause it is really interesting to see how one of these cvt transmissions work. Thank you Ivan for reuploading, this is a video i really wanted to watch before but had a nightmare trying to get the 'paid video' thing to work, i paid the money but for some reason i was not able to view it, had to get a refund in the end. So really good to see it now. It was worth the wait. Very much appreciated.
100SteveB I've literally heard it's the cheap bearings in those pulleys.
Hi Ivan I wish you the best in your new job, I doubt we will see as many auto videos going forward especially if your travelling a lot in your new role! Shame I really enjoy your videos and logic. Your new employer will benefit from that skill
You did an outstanding job with these videos. Excellent mechanical aptitude and analysis skills!
Thank you SO much for doing these videos. You have done the automotive buying public a great service.
I have to wonder if Jatco engineers ever did any FEA modeling on those input shaft grooves and bearings. It seems as if there are extremely high point contact loads there. Even with proper metallurgy and heat treating - the loads at those points may simply be unacceptably high. After looking at the design, it's a wonder they last as long as they do. I suspect that driving style in going to have a major impact on the longevity of these parts. Also, normal variations in metallurgy from batch to batch is probably a significant factor.
I also feel that gov't fuel economy mandates are partly to blame for problems like this. The engineers are pushed into a corner and forced to make compromises that they would otherwise possibly not make if higher fleet fuel economy averages weren't a forced upon them.
Great comment! Yes that is an immense load on 3 little balls 😬
@@PineHollowAutoDiagnostics yeah... But if you think about it--- if the shaft was the real failure, then the belt would have never broke. It would have just sheared those little balls and then the shaft/ pulley would just free spin. So there's no reason that the belt would have broken. What I think happened is that the belt broke first-- and the all the "kibbles and bits" bound up the pulley and so right after failure, she was still on the gas and the shaft and pulley was chewing up pieces of the belt and binding up-- until it sheared those balls. The belt failed first-- it had to.
@@PineHollowAutoDiagnostics Can anyone tell me if Ivan got his money back for the core?
@Chris Bentley Walking and Rambling he did. He said he got his core charge no questions asked
Continuous Vibration & Trouble.
I am stealing this 😉
El Cheapo LOL!!!!! 😂
Keith, how do you find 3-month old comments hahaha
Pine Hollow Auto Diagnostics I am the seer of all 👳🏻
CANNOT VECTOR TORQUE is my definition
I wonder if car makers, having to implement stepped gear changes into CVT boxes is adding more jerkiness and therefore torque spikes into a system that was originally designed for smooth changes of ratio and causing these failures? Nice job with the teardown by the way, enjoyed it muchly!
Great video! Back when I had a car with a CVT I had to know how it worked and am glad to see your tear down. Now I drive a new hybrid CR-V (2023) and its drive mechanism has been fascinating to learn too.
Love your whiteboard demo. Engineering Explained would be proud!
Ivan, you earned your forensic chops with this! Amazing look at a much-maligned transmission system. Seems that new tech always has some as-yet undiscovered bugs; I HOPE that they can work out those bugs.
Thanks for the look inside!
Glad you enjoyed the teardown, Dave!
Seems like what happened is the pulley turned on the shaft, jammed the pulley in place and that caused a build up of pressure when the tcm demanded a ratio change, which caused the seal to blow out. I think tcm changed the secondary pulley ratio enough to snap the belt while the primary was stuck in place.
batchnerd now that's one hell of a good observation!
It's 1500 to 10,000 lbs pressure inside CVTs (don't mess with them while running...) There is no way any seal along the edge of those pulleys can last that long.
Mostly it's contamination/heat that kills them. Should be better filters and coolers!!
This transmission doesn't like dirty fluid.
My question is this: My secondary pulley was damaged (2010 Cube), it was worked on at a machine shop but the sensor i side pulley was damaged. The Versa doesn't have this sensor so I have in mind to put the Versa Transmission ROM pack from a Versa CVT as well as ECM/ECU to make Cube think it's a CVT Versa without the sensor the Cube has. Better than rewriting that code... Ok another scenerio is to put in a Non-CVT from a Versa and use Versa ECM/ECU. Cha Ching!
Any sceptics?? Don't worry about the ignition and radio, trivial.
Are you a Mechanical Engineer? My dad taught us from the time we could toddle around garage “to try to understand how it works”. The “it” depending on what it was, didn’t really matter, that if we understood the mechanics of it, it would be easier to see why it wasn’t working. To this very day, with almost every area of my life, if I understand the how then I can understand the why. So often, people who are paid to fix don’t want to explain why or where the breakdown started. I so appreciate how you show the why...the logic of it all. I’m older now but still find it all very fascinating. Enjoy your channel and thank you for sharing your knowledge!!!
Great video. Had to replace our CVT in a Nissan Rouge. People dislike these transmissons, but they are going to be standard trans on most vehicles as they are very fuel efficient. Hopefully they will improve on them in the future. Once again thanks for the great video.
180k on a cvt before failure is pretty good. I have a new maxima. I think they use a better belt. Still i dont hammer on it. Drag race starts are bad for cars. Drag race starts with a cvt have got to be worse.
One pet peeve is the fake shifting. Means its loosening then tightening the belt to simulate this. Thats the kind of stuff that makes it wear faster.
Texas Car Nerd I agree with the fake shifting part. They design it to not freak out the consumer instead of letting it work to it's full potential. People need to realize how they are supposed to work and be satisfied with it. I find it fascinating there is no shifting and welcome it because it's as good as it gets in terms of power and efficiency. I just hope they design them to be more reliable in the future. For now I'm sticking with older vehicles with manuals.
Subcummins01 AMEN
Dude, did you even watch the whole video?
Cus you're talking as if the problem originates from the belt, and the video clearly shows that its from the grooves in the shaft.
Texas Car Nerd I agree it’s dumb but that’s not what happens. That wouldn’t make sense. Heck. Probably isn’t even possible.
Every type has a specific use...
Really great work! I agree with your comments, it looks like Nissan either needs to increase the hardness of the input shaft (reduce the apparent galling) or add more keyways so that the torque is more uniformly distributed. The latter is most cost effective.
Wow, this series was AWESOME, thank you so much! I hope you got your core rebate! Bought a used (no warranty) Nissan Versa Note S and 4 months later took it in for the 60K check (only had 59K on it) and during the next two weeks the trans would slip, chirp, and jerked a couple times. After watching your video I was able to knowledgeably tell the Nissan mechanic what I thought might be wrong: the wrong fluid, not enough fluid/leak, a bad reprogramming, or low pressure. Of course, on a test drive with the tech nothing happened, which I actually was okay with. They ended up not charging me for the diagnostic and had re-changed the fluid. I had wanted them to check the coolant for metal but they explained how that wouldn't be affected. The car runs much better so I don't know what they failed on previously. I now purchased an extended warranty because I heard CVTs usually fail at about 75K miles, which is utterly atrocious!
Thanks for the comment! Yes proper factory fluid is crucial in CVTs!
The bad design is the high pressure fluid to run everything and everything would fail.
Change the CVT fluid every 30,000 miles max, ignore what it says in the manual which wasn't based on CVT longevity but rather on trying to make it look like it's cheap to maintain. Repeated laboratory analysis of used CVT fluid from the Jatco CVT's shows that the fluid begins it's steep decline in lubricity factors (and reduced thermal transfer capacity) after 30,000 miles of use.
Continuing to run the same batch of CVT fluid until 60,000 miles or more is inviting catastrophic failure as metal to metal contact WILL begin to occur. This also increases the risk of excessive heat damaging the sealed input shaft bearing.
The best way to limit this is changing out the CVT fluid before it starts to degrade. The Nissan dealership I worked at had to practically stockpile CVT units to try to keep up with the failure car owners were experiencing and most of those failures were happening while in warranty and under 60k miles. FYI on your extended warranty.... if you should need to use it due to your current CVT failing be aware that the replacement CVT will not be a new CVT but rather a remanufactured CVT which is simply a used CVT that suffered the same type of death as the one you see in this video and was sent back to Nissan in Japan for a belt swap and then shipped back to the dealerships as a "replacement" CVT.
The problem with this is that by the very nature of the CVT design they are extremely vulnerable to even slightly out of spec variances which can easily occur when a CVT goes through the type of destruction as the one did that he shows in the video. During the CVT remanufacturing process they do NOT test all of the individual components to insure that they are all still in spec, but rather they just replace the obviously damaged parts, slap it back together, and ship them off to be used for warranty claims.
This is why it's so common for a customer to come in with a failed CVT warranty claim and have their failed CVT replaced with one of the Nissan factory "remanufactured" CVT's only for that replacement CVT to fail as well, many times within the first 5k miles of use. I've seen people go through 3 of the remanufactured CVT's within 20k miles. It's precisely because of this that what has become common for people to do with this Jatco CVT nightmare is to do one final CVT replacement under warranty and then immediately trade in the car on something else (not another Nissan lol) before the new "remanufactured" CVT has a chance to self-destruct.
these two videos have been way more exciting to watch than a whodunit movie... suspense increases down to the end, culminating with solving the case, finding the culprit... thanks...
Amen, amen and AMEN!
the torque is actually NOT transmitted through the steel belts...the wicked thing about this type of CVT is that it trasfers force by pushing intead of pulling, that's what the 500-ish metal pieces are for. The belts just hold them together ;-)
The entire auto industry is going crazy right now
Turbo's and CVT's and Push Button Start with Expensive key fobs, Stop Start Technology.
if Under warranty ok that's fine i guess.
Out of warranty where i have to pay to fix it .....noooooo thanks.
Naturally Aspirated, Regular Style Automatic and A normal key for me.
Even an automatic is an inherent pain in the ass. Sure, in start/stop traffic, it takes a lot of stress out of driving, but if it goes wrong, it's an expensive fix, compared to manuals. Disclaimer: talking from a European perspective.
True Agreed. I'm meant more comparing automatic. But yes fair point.
Those Camrys are legendary indeed.
Brian Lawrance i believe it did circle around most cars today
thay are more crazy than that: speakers that simulate engine noise, camless engines, variable compression ratios, non replaceable led headlights,dozens of ecus on each car, even the friggin headlights need an ecu because a relay and a switch is a prehistoric setup and not suitable for the advanced millenial people
Excellent deep dive into the workings and potential failure points of the CVT. I admire your drive to get to the root of the problem and the fact that you would rather try to fix something rather than just throw new parts at it. Cheers !
I watched a Video about 9 months ago about a guy who remanufactures those belts it was amazing how strong they actually are compared to the old rubber and leather drive belts used on almost all older CVT transmission systems on scooters..the early scooters used rollers and centrifugal force to alter the Cone diameters..the CVT is one of the most efficient drive systems after the chain drive on a pushbike.
So- the moral of the story is... Don't stress your shaft until your balls fall out?
HUBBABUBBA DOOPYDOOP LMFAO!
ain't nobody got time for dat
Id die trying...
Did you get the core charge back ok?
I can't believe you dumped all those pieces back in there. It's not like the rebuilder is going to string them back together, like popcorn on a Christmas tree. Thanks for the videos, very informative. Most pro mechanics won't dive in like you did on a CVT trans.
Very awesome belt engineering, thin metal to minimize transverse sheer as well as not reach plastic deformation. That said, it would still have a finite life but obviously other parts fail first so its not a problem.
Great Video!
"shall we put 6 grooves to transfer the torque?" "na three will be enough" 👉🙄
399 belt elements, I counted them as you were dropping them back in 😂
lol
You are outstanding I like the way you think and have the patience and passion to do what you do. It was comforting to me watching both of your video's. I was helicopter mechanic it was fun. You have a passion for this keep up the 👍 good work and Thanks.
I once had a 1977 volvo 343DL with CVT. Belts (note plural) were made of thick rubber and were in AIR. There were 2 belts (one on each side of the car transmission which was in the rear of the car). The outer halves of the primary pulleys were moved in and out by a combination of centrifugal weights and vacuum applied on either side of a diaphragm. The secondary pulleys were just spring loaded. The clutch was a dry clutch (yes you read that right) and the pressure plate had centrifugal weights plus vacuum control too. The engine and clutch unit (i.e bell housing) was in the front, with a very light aluminum prop shaft (rotating at engine speed) in between. The whole setup had 2 disadvantages - it was noisy and bulky. BUT everything was servicable. Changing the clutch was simpler then a manual transmission, and changing the transmission belts only required undoing the tensioning bolts between the main and secondary pulleys and then tightening them again once the 2 new belts were slipped in. So now 50 years later and wiser, when we are supposed to be 're-using' in the interest of the environment, we are instead making all this crap in our new cars that simply ensures we throw away a complete transmission (possibly a complete car ) after 100K kilometers? I don't call that progress. Edit : amazingly th belts are still available for sale : www.volvo340onderdelen.nl/en/volvo-300-serie-drive-belt-non-original-cvt-transm.html
According to your intensive demonstration, I think the cause of that CVT failure is the wear of guide balls/grooves of the pulley due to the bad fluid.
Thank you for your very informative video.
This makes me want to sell my 2016 Altima before the transmission goes out
do it. My 2014 hasn't hit 75K and the transmission is shot. Dealership is giving me the run around now.
Makes me want to sell my rogue with 156k on it
I feel like I'm hanging on to a time bomb
Get rid of it and buy a Camry, Accord with the 2.0t, or Mazda 6.
DallasPilotCar get rid of it..I know someone with 125,000km and having troubles already with the cvt..Nissan will only cover $3000.00 for warranty
Wow....you did an amazing tear down analysis.....wonderful work, and the sort of info people need to see! All I can say is WOW!
Glad you enjoyed the teardown, Quentin!
Excellant synopsis of how the CVT failed. You are brilliant.
Thanks for making this video. It was very interesting. According to Scotty Kilmer, the Toyota CVT is very reliable. My wife's Corolla has a CVT transmission. I don't like how the CVT feels, personally. The engine power does not respond immediately, when you step on the gas pedal. There is a long delay. Somehow Toyota makes it where is feels like it's shifting from gear to gear; but again it really feels sloppy, lots of lag time between the simulated gears. Personally, I would never own a CVT transmission.
Having driven a few different brands of CVT I don't particularly like them either and for much the same reason - that lack of feel of direct drive and the fact the accelerator controls the engine speed instead of just the load. Give me a conventional automatic with a lock-up torque converter over CVT any day of the week.
Jason Hart
You must remember that CVTs are naturally set in *direct drive*
so they "rest" in 5TH gear equivalent.
And the lock-up torque converter disconnects the tranny to the engine to prevent a stall.
Thus: *CVTs will choke back engine response*
|
Theres already a solution to this & Nissan has *always* been doing it to their CVTs:
*Nissan CVTs rest in 4th/5th gear equivalent when in stop & go conditions leaving the lock-up converter to act a dry clutch preventing a stall*
Whenever you are coasting &/or are about to launch the car here's what happens:
*when you slam the gas pedal the CVT will be told to go into 2nd/3rd gear equivalent allowing the engine to reach 3k rpm & then the CVT will shift twice rigidly until you have reached your desired speed & then rests in 6th gear equivalent.*
Scotty is full of s***
Great video. I agree with your analysis that the failure seems to have originated from the primary shaft. Based on the wear pattern it sure looks like the groves wore over time, as the pulley moved in and out. The Aamco manual states the Nissan recommend fluid change interval is 60k miles. If this transmission had 180k on it then that's three times the interval. I think it's possible a breakdown of the lubricant could have lead to the metal on metal contact which made the failure possible. I do think it is somewhat questionable for those small balls to transfer all of the torque of the engine. Seems like some splines might have been better, but maybe they wouldn't hold up to the cycles. They seem to work in manual transmissions, but perhaps the ball and groove solution has less drag. I don't know. It would be interesting to see a new version of the transmission disassembled.
I found a couple additional pieces of information on the CVT. I believe this transmission is the Jatco JF011E. Nissan refers to this CVT as the RE0F10A. The 2009 Rouge FSM confirms it uses the RE0F10A. Not sure if later years use a different CVT as I can only find the FSM for 2009. This transmission is also used by Chrysler it seems. From some of the press I am reading from late 2013 Nissan stepped up it's oversight of Jatco around that time.
akppro.com/en/archive/article/jatco-jf015eaamcoftp.com/sites/aamcotech/assets/cvt-manual_cvt-manual.pdfwww.autoblog.com/2013/12/02/nissan-cvt-jatco-problems-ghosn/
Here's a quote from the akppro.com size comparing and contrasting the JF011E to the JF015E which has a lower torque rating:
"The design of guiding pulleys has changed, too. In the JF011E, pulleys are attached to the shaft with balls, which could be destroyed by constantly changing loads. And here it is pulleys that are fixed with the roller. This is a more durable design solution, which reduces the likelihood of pulley seizure."
So this seems to be what happened with your transmission. I hope the new one is working out alright for you.
But if you think about it--- if the shaft was the real failure, then the belt would have never broke. It would have just sheared those little balls and then the shaft/ pulley would just free spin. So there's no reason that the belt would have broken. What I think happened is that the belt broke first-- and the all the "kibbles and bits" bound up the pulley and so right after failure, she was still on the gas and the shaft and pulley was chewing up pieces of the belt and binding up-- until it sheared those balls. The belt failed first-- it had to.
@@calholli The description of the design change says it "reduces the likelihood of pulley seizure." I'm not in the lab analyzing these transmission failures, but it sounds like if one pulley seized the load on the belt might rapidly increase which could cause belt failure.
@@Fix_It_Again_Tony Yeah.. I just found out on another video that you can replace those little groove engaging ball bearings with a long cylinder pin-- so that it has full contact with those grooves on that pulley shaft, rather than four tiny points on those little circles (the balls)... So yeah, maybe those balls failed first. That's a pretty dumb place for it to fail-- because it's so easy to fix by adding more groves and adding full length pins in those grooves (like I just noted). I bet, once the belt failed-- that pulley could then collapse TOO far, since there was nothing there to grab anymore--- and that's how it blew out the seal and snap ring.
@@Fix_It_Again_Tony The guy rebuilds these--- and he was saying that it's common for those shafts to be beat up like that- by those ball bearings. And you can still grind the burrs off and use Full length pins in place of those stacked ball bearings-- and it still works fine. So I just thought that was crazy, that he knew it's a common problem. smh. Unreal. They should all be recalled and have the pins installed--- this is ridiculous. Everyone knows that if you are using hardened ball bearings, they have to ride in a hardened RACE.. and the fact that those shafts aren't surface hardened to handle it--- or at least have the entire shaft nitrided, is just crazy to me.
☝️👍 Very well done video and part one as well. As a retired Caterpillar mechanic of 45 years, I just can’t stay away from this stuff and still do all my own work. Proper failure analysis is critical to finding the root cause in order to redesign to prevent future failures, and you sir did a fantastic job. I think you were spot on in the failure analysis of your CVT (Constantly Violent Transmission) Thank you for taking the time to do this although I’m not sure Nissan would agree with me 🤔🙃
Thank you for the thoughtful comment! I really appreciate the feedback. As a curious engineer, I couldn't pass up on this opportunity to see how this contraption worked and what caused the explosion :)
You my friend are a true sherlock. Your passion for root cause go's above and beyond. I truely loved this video.
That thing was eating itself from the inside out.
That would of been worth the buck lol .
amazing how the balls in locator grooves on input shaft lasted 180K .
Needed beefing up especially if towing or heavy loaded .
that teardown first time I really grabbed concept of how cones moved and how the belts are formed .
interesting stuff but still prefer cogs myself lol .
Miles, he said miles which= 288km.s
We are in the process of changing our 2004 Cube after having it for 9 trouble free years, all it has cost is regular servicing , tyres and a battery and a set of pads, all the new cube albeit nice and practical and roomy all have CVT...it has really turned me off as I go over 3 mountain ranges once a month, and do a fair bit of running around, I think I have to look for an alternative. Thank you for sharing your expertice. God Bless you mate.
Very Good Report, Thanks, CVT is just a glorified snow machine clutch, we always had to carry a spare belt.
Oops we should have used better steel on that shaft, I can hear it now at the Nissan reman shop - " it appears that two of the belt "vertebrae" completely vaporized! I only count 766 and there shoukd be 768!" NOT!
I think maybe the way the system maintains the proper ratio between the pulleys is that the two oil chambers are connected through the shift control valve . I think you will have a fixed volume of oil between the two. So as you move one, the other kind of floats to keep the same volume or pressure. The shift control valve seems to operate more like a differential valve where you upset the balance and it allows oil to move between the two drums to not only mechanically move the one but move the other hydraulically to keep the same fluid volume or maybe pressure.
So when the drum seized on the shaft, you over pressured the drum and blew the seal as the fluid is non compressible and had to go somewhere. Unhappy things happened as a result.
I like the "unhappy things" theory haha :)
Dude, thanks for posting this series of vids. I've been curious of what goes on inside a CVT for some time. I know the concept and haven't heard much good about them, especially from Nissan. They don't make cars like they used to. Part of me thinks they don't test them well enough or else a lot of problems would be found before mass production. Thanks again!
Your a delightful character.
After my own heart.
I too love to look and tear apart mechanisms to see how they work! The difference being you know basically what you are doing. I usually dont.
Dont ever stop being curious.
This Weber University guy says there are 399 of those metal sections to a belt.
All belts? Who knows.
Very cool tear down.
CVT's in theory are a great idea, because they are similar to to what a snowmobile uses.
Problem is, a lot of them aren't programmed right (early dodge's ) and the strength and long term reliability isn't there yet.
And the fact that most of them are throw away , you often can't buy parts to replace broken items internally.
However some people have good success with them.
Now Me, i wouldn't buy one with my money.
Thanks for the video Ivan, very interesting.
CVT tech is good only for atv, side by sides but no good for on the road vehicles. Too weak to tow with, eventual implosion due to poorly designed tech. These steel belts shed metal within the transmission eventually leading to implosion, the only way to perfect cvt for auto/truck is to go to planetary gearing.
Ivan I have met one of the engeneers working on the development of this gearbox. They have in their vaults the first produced belt. It had 1.000.000. km's been driven with no problems. This type of gear was invented by Hub van Doorne and his team at DAF factory in The Netherlands. Before this in the '60s they produced a automatic transmission with 2 rubber belts used in small cars they accelatated very fast for that time. First with a 2 cilinder boxer engine later with 4 cilinder Renault engine even a F1 car This CVT was later adopted by many Japanese companies as well as Fiat.
Willem Streutgers
I have driven one of the Daf 33 variomatic transmissions, it felt a bit like driving a car with a slipping clutch.
It always sounded like it was revving too high.
Daf were taken over by Volvo in the early 1970's and Volvo produced a similar car to the Daf 33 called the Volvo 343 and 345 (the last digit referring to the number of doors).Volvo used the variomatic transmission for a couple of years but it proved problematic and unpopular and they discontinued it.
I lived in the USA for 19 years and never saw any of the Daf derived Volvos. Probably was never sold in the USA.
Well they are still around here in Europe and very popular as an oldtimers. Those with the rubber bands can still be driven whith one band.
If anyone is interested in reading a bit more about Hub Van Doorne and the CVT push belt, I wrote an article for the Home Metal Shop Club about Hub and the transmission. It starts on page 8 of this newsletter: homemetalshopclub.org/news/12/newsletter1203.pdf .
The 300-series Volvo was fairly popular here in Finland back in the day. Looking back, the CVT was ahead of its time, as the principle hasn't really been used in cars before the 21st century. My buddy's parents had a Volvo 343 in the late eighties too, so I got to experience the ride. I always wondered about the strange tranny and thought something might be wrong with it. One peculiar feature of this tranny was the ability to go as fast in reverse as it did forward. A Finnish car/tech magazine, Tekniikan Maailma, even raced a 300-series Volvo on the track in reverse!
Thanks for the video, Ivan, and cheers from Finland! Been following your channel for some time now, but haven't commented until now.
We in Holland had some funny races all backward with those Daf and Volvo cars.ruclips.net/video/S7ipFApsFec/видео.html Have fun. LOL
Thank you for posting your videos and educating us. Very insightful and much appreciated!
That was my first exploration into a Nissan CVT. Your vid was better than Masterpiece Theater! Keep up the great work!
I have Nissan Altima 2013 SV 2.5L
My Car lose power while I'm driving , and it's not accelerating.
I call Nissan affairs customer service, I asked them if my car has a recall for the Transmission, They told me No, I ask them for Assistant to fix my car.
She said yes, we can open case for you but you have to go to the dealer for diagnostic test, I told her They Asked $200 for diagnostic test. I went there they said it's not the transmission it's the MAF need to be reprogrammed, and I pay $370 for that, problem came again next day, I call Nissan they asked me to do the diagnostic test again and pay another $200
I agreed, in the end they told me Transmission need to be replaced, Nissan Company called me and she said because you have high mileage we will not be able to assist you, I told her you know my mileage from the beginning why you asked me to went to the dealer for the test and pay $370 and $200 and $288. and you already had the decision in advanced?
I recommend every body don't buy Nissan their car is
piece of Junk.
They work with dealer to make money from you
don't buy their car it's not reliable
Well did you get your money back from the MAF and the first diagnostic test I would have or I would have sued that dealership
same problem here. mine is 2010 rogue. lost acceleration on highway. Went through the internet, knowing it is a common issue. then went to delaer, they told you nothing but need a diagnostic. trying to charge you in advance.
From OP's video , I know for sure my car is not deserving spending too much money on it. since change transmission would cost a lot
Lousy metallurgy and bad engineering design cannot be fixed by lubricant quality.
Thanks for exposing Nissan for its lack of engineering competence.
Lot's of things use linear ball bearings, but raceways near to be up too the task and be properly sized.
This 011 series CVT is made by Jatco who btw should have fixed their crappy design years ago.
Nissan should be held accountable but Jatco are ultimately the ones responsible for producing this pile of shite!!!
i love my 2014 maxima. very good cars
last forever
The 010 series CVTs in bigger heavier cars like the Murano, Maxima are actually more reliable despite having to work harder
i guess bc this cars was highway driven for most of the 180 K , i've seen CVT blow up much sooner at around 60 K
Forensic engineering at it's best! You were able to diagnose the failure without
any manual data or diagrams! Highest regards and respect.
Thanks for taking the time for disassembly and investigation. I always wondered exactly how these transmissions operated.
Great troubleshooting and video. I enjoy tearing things apart, too. Putting them back together is another matter.It appears that after the anti-rotation balls liberated from the worn grooves, the pulley was unable to change shape, causing the belt to tighten and fail. The damaged neoprene O-rings were simply a result of overheated and/or overpressurized ATF.The balls and grooves in that roller spline should have been designed to take any load the car could exert--and over many miles. The balls are made of very hard steel and from what I could see, were not deformed. The failed grooves were made of softer steel that wore over time. You did get over 150K on the car, probably over its intended design --life.PS- If you read a new car warranty, the mfr is often allowed to replace any defective part with a "remanufactured part" so some of your CVT might show up elsewhere.
wow man, u r presentation is very cool and enriching. thanks.!!!
I was at the Nissan dealership the other day and was talking to a tech taking one of these apart. I was surprised they didn't just send the CVT into a repair center but they actually fix them at the dealership. Of course they would tell me the failure was because of the remote starter I put in the car 5 years ago...
Thanks for taking the time to put this video together it was interesting.
-Jon
Wow they fix CVTs at the dealership? Wonder what parts they actually replace in there. When I ordered my replacement through the Nissan dealership, it was boxed in a crate, all shiny and fresh-looking. Hopefully it will last a while!
@@PineHollowAutoDiagnostics The dealerships directly are doing more internal engine work and transmission work lately. I didn't think the techs had that kind of training to do rebuilds on this scale. Maybe in the end it's just cheaper to do it that way instead of sending large heavy boxes back and forth to a central re-builder.
My wife just bought a Murano. I remember my parents riding 49cc mopeds by Motobecane Mobyilette with CVT transmission in the 60's. Since she abuses the brakes all the time I think I am good with the transmission and will last. Great video with common sense analysis. Learned what I needed to know.
I just watched your videos on the CVT transmission teardown and diagnosis my question is did you ever get your core charge back on the transmission??? Very very informative video very very interesting
More reasons to love my old 5 speed manual.
Old is gold!
All I could say is you are the best out of the best. Wish your career and knowledge getting better every day. Thank you.
Yes..."What is hiding in the system".... beautifully pursued, thanks so much for bring us along in the investigation finding that shaft failure :)
Excellent video! Totally comprehensive, thank you. Lots of very complicated moving parts, in one of the highest stress and most complicated part of an auto drivetrain. What could go wrong? Everything! Folks avoid CVTs and avoid Nissans. Since they merged with Renault their quality have gone down the toilet. Nissan CVTs are known for reliability issues, and with their new variable compression engines (VCE), it's more of the same, very complicated moving parts. That's why Audi abandoned CVTs. Lots of reliability issues. Honda is using them now and it will come back to haunt them. Avoid these complicated contraptions that are nothing more than expensive reliability nightmares.
You can't chirp 2nd in a CVT!
One of the best vids I've seen. You're awesome Ivan !!!
The cogs in your head work superbly and very smoothly.
CVT belt …. 399 blocks with 2 bands consisting of 12 rings one inside the other on each side of the blocks. For a total of 24 rings. For higher torque applications the bands might have more rings and the blocks would be larger
105,000 on 2013 Altima and the CVT works great. I did change the fluid once. That is recommended. Now I have to keep it to see how far it will go.
213,000 miles on 2013 CVT Accord. Changed trans fluid twice. Still runs like new. My last 1997 Non-CVT Accord was at 356,000 miles when I got rid of it to get the 2013 model. Honda for life.
i own a 2016 Nissan rogue, bought in December 2018, next week i am going for my second transfer case seal failure, it seem to be Nissan it also manufacturing cheap seals, let me hope that AT 205 might keep it from failing a 3rd time
N& CO
There is a reason why Nissan doesnt like trying to sell CVT 4WDs anymore.
Its all because Nissan keeps jinxing up the design.
However the RWD-based Nissan+Infinitis dont suffer such trouble.
Awesome video man. Now my mind can wrap around how the system works. My wife's 2016 Altima CVTjust went out at 59 000mls, luckily under warranty. Hopefully it'll be rebuilt with better parts because it is a nice car otherwise and she loves it. God bless
...A non-knowing guy's question...
Snowmobiles, over 50 years ago (i was a young kid when i sa my first) always used CVT's and still use them today.
The main difference is that snowmobiles use rubber belts that can be field replaced.
I know that there's a power level difference between a snowmobile and a car, but having a transmission that can be easily serviced with a new rubber belt and an enclosed, not user-serviceable friction transmisson, i'd prefer the rubber belt model.
I have a 2017 nissan with, what I'm hoping is, the 3rd generation xtronic cvt (dont know if 2017 models got them). Hopefully, that shaft flaw is fixed in the 3rd gen(?)
watch out sir, your Nissan might be next CVT tran issues
tarasded
Buddy
if you always remember to flush the CVT every 25-50k intervals at the dealer,
Your transmission wont seize this guy's video!
Now, I know why people say to change the trans Fluid every 30,000 on Nissan Cars...
It’s not just the transmission fluid. The filter inside the oil cooler with all the rubber o-rings and the oil pan filter and gasket must be replaced every 60,000 miles too.
It works like a snowmobile clutch and driven pulley. Thanks for making the video!!
Probably best root cause analyze I saw before. Seem like the system has enough pressure to crack the belt in case of missalignment situation.
Great job, I have enjoyed the video!
Good luck.
Excellent movie! Submit this to engineering disasters. The damn little balls or subpar metals. tisk tisk
designed obsolescence
precisely
Planned
Rolling Pile of Junk
Put $50 aside every month during loan life for the inevitable repair
Good way to go out of business.
After watching this, I have a whole lot more respect for how delicate a transmission is. No more neutral drops and 60 second burn outs for this boy....Well at least not with a CVT transmission. Thanks
Dude!
The level is depth to your explanations is awesome!
I'm not a mechanic, but I do love videos like these!
I can't wait to watch more from you man!
Just found your channel!
Are you an engineer?