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CVT and Automatic question

Do you have to change the belts for the Toyota CVT transmission?

Those belts are meant to last the life of the vehicle.

Toyota hybrids don’t have a belt. Their non-hybrid CVTs have a lifetime belt.

Just keep thinking lifetime is over, cynical me

Here is an explanation of Toyota’s eCVT:

That being said, I am not aware of any modern CVT that uses a belt. To the best of my knowledge, they all use a fairly wide roller chain nowadays. If I am incorrect, I am eager to be corrected, as I like to learn at least one new thing every day.

And, if anyone thinks I am splitting hairs on this issue, then think about all of the times that we have corrected people who think that their engine has a timing belt when–in fact–it has a timing chain.

A belt is a belt, and a chain is a chain, and the difference–as we should all know–is significant.

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I understand that the CVT belt is not rubber. Judging by the two rebuilds I watched on YouTube, they can be of quite unusual construction. When I think of a “chain”, I think of something meshing with a cogged gear, not something constantly rubbing against its edges. I don’t think I will buy into the CVT idea until the belt and cones are mounted in such a way that they are easily replaced.

Belt=continuous band of material used to transfer motion.
An e-cvt does not have a belt.
The article shows a belt. It says it does not use a belt.
This is a pic of a “belt” that we don’t use.
Thanks

Nissan uses a “chainbelt” or “beltchain” :slight_smile:
It consists of hundreds of small plates sandwiched between two steel rings.
The resulting structure looks like a belt, acts like a belt… but they use it not for pull-motion, the torque is transferred in push-motion.
AFAIK they are not alone and Subaru uses the same concept.
Why Nissan’s CVT fails so often is because they decided to make pulleys from mud&sticks, where Subaru made them with massive splines, resulting in substantially less hard-failures.
Both are made on the same JATCO plant :slight_smile:

AFAIK Ford uses the actual chain

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Here’s a picture of the Subaru CVT chain clamped by the cones with a mirror like surface. Notice the alternating plates in the links with no room for teeth to poke through the holes to drive the rollers.
image

And here’s a picture of an engine’s timing chain. Notice the wheels with teeth pushing on the rollers.

Just because Subaru uses a chain in its CVT, it doesn’t work like a timing chain. Rather than transmitting power by pulling on the rollers using teeth around a wheel, the cones clamp hard(using a portion of the engine’s input) on the chain and pull on the chain as they rotate, with a possibility of catastrophic slippage if the cones don’t grab the chain hard enough.

CVTs have a place in Japan, where the streets are narrow and their compact size allow for greater steering angle. Let it stay there, until big trucks with CVTs start delivering water melons to your local market. Audi tried it in the A4 before they ditch it in favor of the conventional 8 speed zf and dual clutch. As I posted recently, Nissan will use the ZF 9 speed on its Pathfinder/QX60 twin in favor of the JATCO CVT. Even Subaru doesn’t use it on its BRZ.

Well, you could buy an Infiniti with variable compression motor and cvt. Then you have 2 things to worry about.

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AFAIK Nissan was also toying with the idea of “high-torque CVT” for their trucks, where it is no belt or chain, but something resembling the planetary gear-set with cones in place of cogs for sun and ring “gears” and tilt-floating “planet gears” in the middle.
I’m not sure if this is not yet another disaster in making, but concept is interesting.

image
That’s a toroidal CVT. Round disks are clamped between 2 curves discs. The round discs are tilted continuously to mesh with the different diameters of the curved discs.

The idea of using CVT is to keep the engine operating at its most efficient range. But any gain in operating efficiency is largely negate by the need to power pumps to provide clamping on the belts, chains, discs, to the point where its efficiency is roughly on par with a manual.

The metal surfaces are supposed to be separated by a thin film of special CVT elixir that turns to a glass like solid under high pressure to prevent them from scouring each other. We know how well that works out.

Yep, especially with owners skipping on the fluid maintenance… it’s “lifetime” after all :slight_smile:

I have been researching the Nissan Rogue as I can get a used one cheaper than others and some other factors. Seems like their newer CVT’s are having decent lifespan esp if the fluid is changed. I might be wrong, so looking for some data here other than historically claiming all Nissan CVT’s fail at X miles.

Well, newer ones are…newer. So they may last longer, they may not. The Subaru engine problems took a while to show up. We got a used 2007 Forester, it showed ‘good’ in CR, then a few years later it listed engine problems for that year.

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It may be newer, but the it is fundamentally the same design. It has to be protected against slippage. A few weeks ago, my cousin drove us in his brand new Honda fit with a 1.5l engine and a CVT. during a climb similar to most freeway on ramps, he said the car could not get up to 50.

My xB with a 1.5l engine from the late 90s and a manual had the same problem, when I started at 7000’ higher in elevation. I either redline in 2nd at half throttle or floor it in 3rd, risking overheating; and we had 3000’ to climb. It seems that the newer engine was programmed to provide less power to protect the transmission.

There’s nothing wrong with using software to protect the machine but the machine itself, which is supposed to be newer and better. I’m not against the concept of CVT. it would be great on trucks, where a missed gear on a downhill can kill people. You can’t miss gears in a CVT. I’m just not buying the current implementation of CVT

Is the e-cvt trans available in a non hybrid Toyota? Sounds interesting. Except for the hybrid part.

No, it’s part of the hybrid system.

If you drive it until the battery would not accept any charges, you’d have an eCVT minus the hybrid part

See my previous post.