Kizashi Club

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 #47913  by DiggerDerrik
 Sun Sep 30, 2018 4:33 pm
Last night I ran down a YouTube rabbit hole. Came across a 2 part video series from a guy who had a CVT failure on his Nissan Rogue at 186K. In the first video, which doesn’t provide much in terms of conclusions, he disassembles part of the tranny and finds that the belt has come apart. In the second video, which I’ve posted, he comes to the conclusion that the belt failed when the input drive pulley locks up. This was caused when the metal balls used to allow the pulley to move on the shaft sheared off and wedged themselves in between the pulley and shaft. Locking up the pulley and causing the belt to fail.

He did an excellent job in the videos of tearing apart, explaining, and coming to a final conclusion. If this is indeed the most common failure point, would more frequent fluid changes have prevented this? I lean toward no. The balls are subject to shear force. Over countless rotations and pulley adjustment movements on the shaft they wear a larger grove into the shaft and eventually shear or possibly disintegrate.

Curious what others think.

https://youtu.be/_64zEsMdQ9A
 #47914  by KuroNekko
 Sun Sep 30, 2018 7:20 pm
But aren't the pulley shafts and bearings lubricated? If so, then the fluid (considering age, condition, purity, etc.) would have a lot to do with wear. While there are differences by inherent nature, motor oil works to prevent wear on parts like bearings and shafts and synthetics do an impressive job in not only keeping components cleaner but providing better protection against wear in this regard. I can't imagine that transmission fluid in a CVT would not serve a similar purpose in some regards to not only cool but to lubricate. If my assumption is correct, then the condition of the fluid would have a lot to do with wear resistance.

Your post also had me very interested in the lubrication of CVTs. While it's hard to determine exactly which parts are lubricated, I came across a number of research articles on the lubrication of CVTs and it's quite obvious that the fluid lubricant is imperative in the proper functioning and longevity of the CVT pulley and belt. Most of these articles state that friction between the belt and pulley surface has the highest stress in a CVT and is the greatest failure point of the CVT. In essence, there is more to worry about than just the input shaft lubrication and its effect on the belt from wear.

Now, I'm no engineer and don't even own a vehicle with a CVT but my understanding of all this only seems to hint one thing: CVT lubricant changes are absolutely imperative to the longevity of the transmission. It's shocking that some automakers treated the fluid as "life-long" given the research that suggests otherwise (stressing the importance of friction-modifying additives) and given the fact that CVTs have an alarming failure rate at high mileage.

Here is one article that focuses on lubricants in CVT and their effect:
https://www.hindawi.com/journals/at/2012/476028/

Edit:
I watched the video in the first post (which I somehow missed before my initial reply). It's obvious the input shaft and bearings are lubricated by the fluid as is the belt and pulley to state the obvious. While the wear from the pressure does seem excessive, the only thing that could mitigate that would be the CVT fluid. While I agree with the mechanic that the design should be revised to alleviate the amount of wear from pressure, it's quite obvious to me that fluid condition is paramount to wear resistance and CVT component longevity.
If I owned a CVT, the fluid would get drained and refilled every 30,000 miles, just like a conventional automatic. Nothing that deals with constant heat and friction modification should ever be considered "replacement free" in my mind.
 #47919  by DiggerDerrik
 Sun Sep 30, 2018 8:13 pm
I left out the part in my initial post where he determined basically the failure was due to poor design. Stating that there should either be larger balls or more of them. That’s where I started questioning the likelihood of fluid changes preventing this.

I watched both videos. Though I did fast forward several times being that they’re over 1.5 hours between the 2 of them. I never heard him mention fluid changes. I have no clue if Nissan called for them or not but I would assume a guy with the knowledge to change his own transmission would also follow manufacturer guidelines if they did call for them.
 #47920  by KuroNekko
 Sun Sep 30, 2018 9:46 pm
DiggerDerrik wrote:I left out the part in my initial post where he determined basically the failure was due to poor design. Stating that there should either be larger balls or more of them. That’s where I started questioning the likelihood of fluid changes preventing this.

I watched both videos. Though I did fast forward several times being that they’re over 1.5 hours between the 2 of them. I never heard him mention fluid changes. I have no clue if Nissan called for them or not but I would assume a guy with the knowledge to change his own transmission would also follow manufacturer guidelines if they did call for them.


The video you linked has the part where he mentions towards the end about poor design and the need for larger ball bearings. However, where I disagree is whether or not fluid changes can mitigate, if not prevent, this. After all, those ball bearings are lubricated by the CVT fluid meaning they are subject to the fluid's condition. If the fluid condition can't entirely prevent it, I still believe it may mitigate and delay the wear. The regular changing of the fluid may be the difference of this kind of wear showing up at 186K vs. 300K+ miles.
Also, it's evident from the video description that the guy in the video is a mechanic tasked to replace the transmission and isn't the actual owner of the vehicle.

Also, you can assume that the CVT from the Nissan Rogue would have had a similar maintenance requirement as the Kizashi's CVT. Both vehicles utilize CVTs made by the same company JATCO. It's also a model year 2010 Rogue which is the same model year the Kizashi debuted. I'm assuming the Rogue's CVT has a similar maintenance schedule as the Kizashi's in that the fluid was considered "lifelong fluid". I'm going by what Ronzuki has stated about the Kizashi's CVT fluid given I don't own a CVT model and have no firsthand experience.

Basically put, I see it like this: the wear that's seen inside failed CVTs show that there are inherent vulnerabilities by design. It's hard to change a design like that after manufacture and sale but these components are subject to lubrication and the quality and cleanliness of said lubrication (CVT fluid). Most wear can be mitigated by lubrication and newer fresher fluid is always better than older dirtier fluid in preventing wear. If anything, this video proves to me why fluid changes are important in these CVTs. The commonly failing parts like the belt and pulley shafts are directly subject to the CVT fluid for lubrication. It's not like the majority of CVTs are failing from TCM or electronic failures.

Thankfully, JATCO designed the CVT with a fill pipe and drain bolt, making fluid changes easier than sealed transmissions that often have hidden filler pipes and no drain bolts. I think everyone should heed Ronzuki's advice in changing out the CVT fluid as their CVT-equipped Kizashis rack up the miles. I believe the new fluid will keep the CVT running cooler and prevent excessive wear.
 #47921  by DiggerDerrik
 Sun Sep 30, 2018 9:59 pm
KuroNekko wrote:
Also, it's evident from the video description that the guy in the video is a mechanic tasked to replace the transmission and isn't the actual owner of the vehicle.


In the opening part of the first video he states the Rogue is back on the road and his wife is driving it.

I don’t disagree with anything you’ve said. I posted this video for a couple reasons. One being that at least this video shows what has failed. We’ve had a few posts talk about CVT failures and there are posts on the internet about other brands with them too. However I don’t recall ever hearing what the actual cause was. Two I want to hear what other members thought about the info provided.
 #47928  by bdleonard
 Tue Oct 02, 2018 2:31 pm
KuroNekko wrote:Also, you can assume that the CVT from the Nissan Rogue would have had a similar maintenance requirement as the Kizashi's CVT. Both vehicles utilize CVTs made by the same company JATCO. It's also a model year 2010 Rogue which is the same model year the Kizashi debuted. I'm assuming the Rogue's CVT has a similar maintenance schedule as the Kizashi's in that the fluid was considered "lifelong fluid". I'm going by what Ronzuki has stated about the Kizashi's CVT fluid given I don't own a CVT model and have no firsthand experience.


The 2010 Rogue uses the same Jatco JF011E transmission used in the Kizashi (Nissan also calls it the RE0F10A) with one notable difference. Without the "tow package" the Rogue lacked a secondary CVT oil cooler (which the Kizashi has always had) and the Rogue was very prone to overheating the CVT fluid. That was very tough on the fluid, and the transmission. Nissan eventually released a service bulletin and kit for adding a secondary CVT cooler to that generation Rogue: https://static.nhtsa.gov/odi/tsbs/2015/ ... 7-2280.pdf
 #47929  by KuroNekko
 Tue Oct 02, 2018 5:27 pm
bdleonard wrote:
KuroNekko wrote:Also, you can assume that the CVT from the Nissan Rogue would have had a similar maintenance requirement as the Kizashi's CVT. Both vehicles utilize CVTs made by the same company JATCO. It's also a model year 2010 Rogue which is the same model year the Kizashi debuted. I'm assuming the Rogue's CVT has a similar maintenance schedule as the Kizashi's in that the fluid was considered "lifelong fluid". I'm going by what Ronzuki has stated about the Kizashi's CVT fluid given I don't own a CVT model and have no firsthand experience.


The 2010 Rogue uses the same Jatco JF011E transmission used in the Kizashi (Nissan also calls it the RE0F10A) with one notable difference. Without the "tow package" the Rogue lacked a secondary CVT oil cooler (which the Kizashi has always had) and the Rogue was very prone to overheating the CVT fluid. That was very tough on the fluid, and the transmission. Nissan eventually released a service bulletin and kit for adding a secondary CVT cooler to that generation Rogue: https://static.nhtsa.gov/odi/tsbs/2015/ ... 7-2280.pdf


I looked into it given I found it odd that a four door family sedan had a trans oil cooler but not a CUV despite these typically being "tow package" features. One is far more likely to tow with a CUV than a sedan so it was puzzling.
This is what I found:
You're right that the Kizashi came with a CVT fluid cooler standard. The Nissan Rogue featured a small filter-looking cooler for the CVT fluid that was cooled by coolant heat exchange but under demanding conditions, it was just inadequate. The Nissan service bulletin cooler looks to be a unit that runs the CVT fluid from the original cooler apparatus into a radiator cooler which is nearly twice as big as the Kizashi's CVT cooler. The size reminded me of the RRM aftermarket CVT cooler for the Kizashi and had me wondering if the larger Nissan CVT cooler would fit in a Kizashi.

That being said, again, I think most issues can be alleviated with routine fluid replacement. Most people on newer CVT fluid report that their Kizashis run better under demanding conditions and don't exhibit the whine that's often associated with demanding driving (which also means the fluid got more hot).
 #47930  by bdleonard
 Tue Oct 02, 2018 8:42 pm
I agree that regular fluid changes are the best preventative maintenance. I did one early drain and fill at 10k, another at 30k, and plan to do them about every 30k going forward. As for the Rogue cooler kit, the cooler is only 6" tall x 11" wide vs the Kizashi cooler that is approximately 3" tall x 24" wide. Assuming a similar fin design (similar surface area), I'd guess they cool about equally well. The Rogue is a reasonable comparison to the Kizashi for these purposes, as they used the same transmission and had very similar power and vehicle weight
 #47931  by KuroNekko
 Tue Oct 02, 2018 10:42 pm
bdleonard wrote:I agree that regular fluid changes are the best preventative maintenance. I did one early drain and fill at 10k, another at 30k, and plan to do them about every 30k going forward. As for the Rogue cooler kit, the cooler is only 6" tall x 11" wide vs the Kizashi cooler that is approximately 3" tall x 24" wide. Assuming a similar fin design (similar surface area), I'd guess they cool about equally well. The Rogue is a reasonable comparison to the Kizashi for these purposes, as they used the same transmission and had very similar power and vehicle weight


Ah, I didn't realize the Kizashi's was that long across given I've never seen it in person. I guess if cooling was absolutely a priority, one can go with an external cooler, JDM-style. Any takers?

Image
 #47960  by DiggerDerrik
 Sun Oct 07, 2018 4:07 am
Small update. The video I watched to spark all this was part of a (I think) 7 part series. I watched part of the first one where he diagnoses the CVT failure. He did state it was the original fluid. So 186K on the fluid. He also stated the Rogue had a fluid life monitor and said the fluid was good for another 100K. :facepalm: