How your CVT works

[Daox]

I think there is a lot of misinformation out there about CVT transmissions in general. They're a newish technology for cars and most probably don't really know how they work. This thread will hopefully help deal with that by providing information on CVTs in general. For more information pertaining specifically to the Mirage's Jatco CVT7 JF015E, see this thread which has specifications and features of the JF015E.

There is obviously a bad stigma from years ago when Nissan, Chrysler and other companies first started using CVTs. They were not that reliable over time. However, it remains to be seen how these newer CVT transmissions will hold up. Thus far (it is 1/25/17) I haven't heard of any CVT failures, and there are some CVT owners with a fair amount of miles on their car.

So, rather than me typing a ton of stuff, I found a couple of videos that show how a CVT works, and how it is made. This is not the transmission from the Mirage, but it is similar in operation.





This video shows the details of the metal belt. It explains how it is made, assembled, and a little about how it is used. For example, did you know the metal belt actually pushes the driven pulley instead of pulling it? I did not.





As I find more info on CVTs, it will be posted.

[MetroMPG]

Neat video - I'd seen one but not the other.

And I did not know that the belt PUSHES instead of pulls.

Thus far (it is 1/25/17) I haven't heard of any CVT failures, and there are some CVT owners with a fair amount of miles on their car.

I haven't heard of any Mirage CVT failures either. Considering the Mirage is now in its 5th year of production, and its JATCO CVT-7 has been used in numerous vehicles for 8 years, I think it's safe to say this one is probably well-designed & built.

[MightyMirageMpg]

The first videos pretty cool. Hard to believe with such a narrow contact patch it doesn't just slip.

Wish they would explain the clutches and such a little more. Maybe it's my lack of knowledge but that surely appears easier to service than a regular automatic.

[Marklovski]

CVTs are actually great if you want to supercharge your car. Cuz a CVT avoids some issues including any power that would be lost (or wasted) on an automatic or manual.

[Eggman]

So, rather than me typing a ton of stuff, I found a couple of videos that show how a CVT works, and how it is made. This is not the transmission from the Mirage, but it is similar in operation.

Great videos, especially the second one.

CVTs are actually great if you want to supercharge your car. Cuz a CVT avoids some issues including any power that would be lost (or wasted) on an automatic or manual.

Interesting. I thought there was power loss through the hydraulic system of any automatic transmission. Maybe I misunderstand you - could you help me see what you mean about power loss? I figure the manual would be more efficient at transferring power.

[Marklovski]

The CVT can run on the highest boost almost all the time. The TPS input can respond without RPM being the main factor. The CVT controls the trottle and boost where it can get back any possible lost power, the power lost won't really be that much but its at least something.

Edit: i would recommend turbos for manuals. Turbos are way better imo. Also, im talking about centrifugal superchargers not any other kind.

[miragefan17]

does anyone know what other veichels use the cvt 7?

[Fummins]

According to wikipedia the cvt 7 was used in : Mitsubishi Mirage, Mitsubishi Delica D:2, Nissan Cube, Nissan Juke, Nissan Latio, Nissan March, Nissan Note, Nissan Sylphy, Suzuki Alto Eco, Suzuki Hustler, Suzuki Solio, Suzuki Spacia, Suzuki Splash, Suzuki Swift, Suzuki Wagon R
I've yet to see a Nissan versa or Nissan cube with a similar looking transmission as the Mirage.
Though the only one can confirm first hand in a 2014 Chevy spark, they use the same filters at least though the oil pan has one less bolt I believe.