Jatco CVT with a chain

[JTK]

Originally Posted by bbhero
Huh... Interesting... Wonder what belt my car came with being it is a 08 VQ??



Yours would be a belt.

Interestingly enough, even the ~285hp VQ35 powered 2020 Nissan Murano, which is basically just a sportier Pathfinder has the belt version and only a 1500lb tow rating.

 

[nascarnation]

Originally Posted by Lubener
Originally Posted by JTK
Just to add to the above. The chain has been used since the 2013 Pathfinder came out, thus the 5000lb towing capacity of the 2013-2016 model years and 6000lb for the 2017+. 2017+ got the extra 1000lbs due to the direct injected engine.

I can recall a chain being used in GM's older units from the 90's (4T60E).


But that 4T60 chain is much different in function, essentially like the one in most 4x4 transfer cases. It's a chain between two toothed sprockets The chain in a CVT transfers torque via friction.

 

[PimTac]

I believe Jatco fixed the CVT problems around 2016 or so when they came out with their CVT8 models. Reliability greatly increased after that.

This was after then CEO Ghosn made that ultimatum to Jatco as the problems were widespread.

It has also been mentioned here that larger engines of 2.5 liters or more seem to run better with CVTs than smaller engines. There is some truth to that. I have driven rentals with a CVT in both small and larger engines and I found that to be the case. The CVT units are not the same. Some info in the link.


https://www.jatco.co.jp/english/products/

 

[D1dad]

The cvt is fine. Yes a few failed under a normal warranty and some (my own) failed under the extended warranty @90k. My son in law is a GM tech and does at least one tranny a week. To say that a cvt is gonna fail faster than a Chevy or ford is inaccurate. My FIL went through 3 trannys under warranty in his super duty that he had a construction trailer hooked to full time. The hate for cvt's goes along with their weird design and the cost to replace them. I've been driving an impala for the last few months and let my son take the Altima back to college, when I jumped in it last week it was weird, but made me realize how smooth they are and how much I like them.

 

[PimTac]

A lot of the CVT hatred is simply the case that people were used to feeling a shift. It was a new paradigm to get used to. At first I didn't care for them either but later on I got used to how they work.

 

[D1dad]

I loaned my altima to my dad when his car was in the shop. He got 5 minutes down the road and called and told me my tranny was slipping. He's still blown away by the cvt but he's a three on the tree guy.

 

[JTK]

Originally Posted by PimTac
A lot of the CVT hatred is simply the case that people were used to feeling a shift. It was a new paradigm to get used to. At first I didn't care for them either but later on I got used to how they work.


A lot of it too is people's experience with them is with an abysmal 4cyl engine in econo-car format. The newer 4cyl/CVT combos are much better and driving anything with a Nissan VQ35 and CVT is an absolute hoot to me. They really toss you back in your seat.

 

[SwampSurvivor]

I think it works perfect with econo engines. The Fiance's Leaseon Sentra can cruise at 1200 RPM down US11 and get 45 MPG according to the lie-o-meter and it's able to hold itself in peak RPM when hopping on the Interstate.

 

[MolaKule]

In my PathFinder the CVT is programmed to give a small "bump" feel. I want a smooth gear transition in a CVT and have not been able to get the computer reprogrammed to do that.

 

[D1dad]

Originally Posted by JTK
Originally Posted by PimTac
A lot of the CVT hatred is simply the case that people were used to feeling a shift. It was a new paradigm to get used to. At first I didn't care for them either but later on I got used to how they work.


A lot of it too is people's experience with them is with an abysmal 4cyl engine in econo-car format. The newer 4cyl/CVT combos are much better and driving anything with a Nissan VQ35 and CVT is an absolute hoot to me. They really toss you back in your seat.

While I have no proof that your wrong, the Nissan tech who replaced mine said the opposite of the earlier cvts. Said the vq35 was more likely to tear up a cvt due to the power transfer. Yet my wife's murano had 200k with no issues that required attention. I truly believe that the cvt was a hit or miss but so was the tranny used in many a GM vehicles.

 

[JTK]

Originally Posted by D1dad

While I have no proof that your wrong, the Nissan tech who replaced mine said the opposite of the earlier cvts. Said the vq35 was more likely to tear up a cvt due to the power transfer......


Could very well be. I forgot that the Murano came out in 2002. Those were the early days for the CVT and it was coupled to a VQ35.

 

[D1dad]

Originally Posted by JTK
Originally Posted by D1dad

While I have no proof that your wrong, the Nissan tech who replaced mine said the opposite of the earlier cvts. Said the vq35 was more likely to tear up a cvt due to the power transfer......


Could very well be. I forgot that the Murano came out in 2002. Those were the early days for the CVT and it was coupled to a VQ35.

Ours was an 07 and outside of my 03 altima was one of the best cars we ever owned. Even my altima was spared by the certain engine death caused by the cat being sucked up in the motor. I honestly didn't know a thing about it until after the car was totaled with 176k on it, but the car never used a drop.

 

[JTK]

Just a fun fact to add in regards to this unit. They have a externally mounted cartridge filter! Not sure if this applies to the Murano and other present VQ35 powered Nissan CVTs, but it's a first as far as I know. https://youtu.be/LA03r5gNzFU

 

[chunt]

Originally Posted by JTK
Just a fun fact to add in regards to this unit. They have a externally mounted cartridge filter! Not sure if this applies to the Murano and other present VQ35 powered Nissan CVTs, but it's a first as far as I know. https://youtu.be/LA03r5gNzFU

Nice to know about the filter. But the video has a few errors. He said that you cannot refill through the dipstick tube. When I did my drain and refill I used the dipstick tube to refill. With out Nissan's special tools using the dipstick tube is the only way to refill. And a drain and refill takes about 3 1/2 quarts on a 2017-18 Pathfinder. He also removed the level check plug (he called it the fill plug) with the engine off which is something you should never do.

 

[JTK]

Oh for sure on the errors. This guy refilled thru the level check plug, which you can do, but it's silly to do so when you've got the charge tube.

The 6qt thing is definitely way off and he also stated NS-3 is green and not blue.

My only take away on that video was the filter.

 

[Exhaustgases]

A thread resurrection of sorts, I just found this during a search.
I can understand the desire to have a chain rather than the push belt, but it seems to me a bunch of pulley to belt contact is lost with that chain.
Along with that more slippage of course between the contact faces. I personally think the main failure mode in these CVT's is like in many other modern mechanical devices. Choice of the wrong materials, improper heat treats, lack of good QC. All of course to cut corners and make it cheap and easier to manufacture. Valves etc. sticking ? In the old days of cast iron valve bodies I don't remember too much sticking and wearing of valve body parts, but then regular automatic transmissions are not designed to have something that is always in slippage mode, ie the belt or chain of a CVT, that will of course shed small micron size metal particles that a suction screen will allow to pass on. It is a transmission that should have a fluid change as often as the engine oil is changed, if you expect it to last at all.

 

[JTK]

A thread resurrection of sorts, I just found this during a search.
I can understand the desire to have a chain rather than the push belt, but it seems to me a bunch of pulley to belt contact is lost with that chain.
Along with that more slippage of course between the contact faces. I personally think the main failure mode in these CVT's is like in many other modern mechanical devices. Choice of the wrong materials, improper heat treats, lack of good QC. All of course to cut corners and make it cheap and easier to manufacture. Valves etc. sticking ? In the old days of cast iron valve bodies I don't remember too much sticking and wearing of valve body parts, but then regular automatic transmissions are not designed to have something that is always in slippage mode, ie the belt or chain of a CVT, that will of course shed small micron size metal particles that a suction screen will allow to pass on. It is a transmission that should have a fluid change as often as the engine oil is changed, if you expect it to last at all.

Agreed and I believe this it's why you seem to read of less problems with the Murano's belt CVT vs the Pathfinder's chain CVT, even though the rest of the engine and chassis is the same between the vehicles.

Oddly enough, there's lots of folks out there that tow upwards of 6000lbs with their 2013+ Pathfinder and I've yet to hear of one fail when towing.

 

[meep]

I think one of the keys to improving driver experience with a CVT is to refine the engine dynamics, especially the I4s. Since CVTs will gladly let the smaller engines spin up to 4-5k rpm, it really sours the experience if the engine sounds like arse at those speeds, like it’s grinding coffee beans and is thrashing up there with odd vibrations. Otoh, when the CVT spins up a well-balanced engine and it just sings, I’m much more all right with that.

 

[Ken42]

Apparently Jatco has gone with a chain as opposed to their typical belt on some of the JF017E units used with VQ35 engines. I didn't know this. Sorry if it's been posted.

That’s a Luk unit. From Germany. Best you can get. Subaru uses them

 

[SoNic67]

My mom went through not 1 but 2 traditional 4 speed automatic transmissions in her 99 Ford Expedition in less than 160k miles... A Lincoln Mark 5 or 6 whatever one it was the transmission went out in less than 130k miles... A Pontiac Grand Prix a traditional 4 speed automatic transmission went out 2 times in less than 6k miles. .. So much for that great reliability of the 4 speed automatic transmission...

I had a 2001 Ford Explorer with 4 speed auto that lasted 200k miles commuting, city traffic (rust got to brake lines). I also had a 2001 Mercury Sable with 4 speed auto that lasted 180k miles (totaled by teen driver).
However I did keep the maintenance for heavy usage (drain and refill schedule 40-60k miles), unlike many people that think that "reliable" means "no maintenance" whatsoever.
The automatics driven in a modern city stop-and-go traffic, in lower US latitudes (temps more than 90 deg F) need that.
The transmissions that last 200k miles driven on highway from Michigan to Florida twice a year have a much better life. Highway miles are 1/4 of normal miles, there is almost no shifting, no clutches wear, no torque converter heating up (being locked up most of the time). CVT's are kept at constant ratio...

As for manual transmission snobs: in the same stop-and-go traffic, they will eat up clutches. Or, to avoid that, they are the slugs that are driven in the left lane and leave 10 car lengths in front of them. And everyone with an auto cuts them off, and they hit brakes. Determining the traffic to became stop-and-go.