CVT Rocks

[WhizkidTN]

Originally Posted By: PandaBear
Originally Posted By: philipp10
Most of your post was pure [censored]. You honestly think all these manufacturers are betting the farm on a bad technology? I don't.


Manufacturers have been using bad technologies all the time: Honda V6 VCM, Honda V6 auto transmission from 2000-2003, BMW carbon build up, Lexus IS250 V6 carbon build up, GM V6 nylon intake manifold head gasket, Ford Taurus transmission, Nissan intake butterfly that suck in a loose screw.

As for CVT, as recent as 2006 Honda Civic GX has transmission issue on the CVT that will grenade before the CNG tank expires. People are buying the earlier automatic models to avoid the CVT.


Yup, I got burned by the 2002 Honda transmission "issue" on my Odyssey mini-van. It finally died at 156K miles. Sad since nothing else was wrong with the minivan (I owned it for 6 years). I nursed it with fluid changes, the TSB modification of the extra oil cooling port, external inline Magnefine filter, etc. Still died. Traded for the Rogue and got a 10yr/120K miles bumper to bumper warranty to cover the CVT "just in case".

 

[JTK]

Originally Posted By: WhizkidTN

Yup, I got burned by the 2002 Honda transmission "issue" on my Odyssey mini-van. It finally died at 156K miles. Sad since nothing else was wrong with the minivan (I owned it for 6 years). I nursed it with fluid changes, the TSB modification of the extra oil cooling port, external inline Magnefine filter, etc. Still died. Traded for the Rogue and got a 10yr/120K miles bumper to bumper warranty to cover the CVT "just in case".



How old was the 2002 Odyssey at 156K miles when the AT went out? 156K miles is very good for a transaxle to last in any minivan. I'm not sure I would consider this as being burned. Frustrating yes- especially if the rest of the vehicle is still great. Then again, I come from an area where vehicles are a rusted mess by 10yrs/120K miles.

 

[CommandoDude247]

My experience has been 100% positive thusfar. Vehicle is a 2013 Nissan Juke NISMO with the CVT/driver selectable AWD system. FWIW if you want AWD in the Juke you can only get the CVT, unless that has changed in newer models. 6 speed manual is FWD only. Has 43,000 miles on it and still super smooth. I take a look at the fluid level/color periodically and it still looks/smells fine. The car drives like a direct drive electric car in that the power delivery regardless of RPM range is fluid-like, no jerking/shuddering, etc as I have read some CVTs can do. You can shift it manually for a geared feeling, which has pretty good feel to it and thankfully has no rev limiter kicking in.

For my vehicle it's recommended the dealership do a 1 qt. fluid analysis at 60K miles and either leave it be or change it based on that. Because of the vehicle having the ICON system (selectable ECO, NORMAL, SPORT modes), the CVT and AWD system I opeted for the extended 8 yr/120K warranty.

 

[WhizkidTN]

Originally Posted By: JTK
Originally Posted By: WhizkidTN

Yup, I got burned by the 2002 Honda transmission "issue" on my Odyssey mini-van. It finally died at 156K miles. Sad since nothing else was wrong with the minivan (I owned it for 6 years). I nursed it with fluid changes, the TSB modification of the extra oil cooling port, external inline Magnefine filter, etc. Still died. Traded for the Rogue and got a 10yr/120K miles bumper to bumper warranty to cover the CVT "just in case".



How old was the 2002 Odyssey at 156K miles when the AT went out? 156K miles is very good for a transaxle to last in any minivan. I'm not sure I would consider this as being burned. Frustrating yes- especially if the rest of the vehicle is still great. Then again, I come from an area where vehicles are a rusted mess by 10yrs/120K miles.


12 years old at the time of transmission failure. Never pulled a trailer or abused it. I normally drive my cars to 250K+ and normally buy used (except for my last two "new" cars). Being a Honda and an Honda minivan, I expected 250K~300K with excellent maintenance. Didn't get it due only to the known problematic transmission.

 

[PandaBear]

Originally Posted By: JTK
How old was the 2002 Odyssey at 156K miles when the AT went out? 156K miles is very good for a transaxle to last in any minivan. I'm not sure I would consider this as being burned. Frustrating yes- especially if the rest of the vehicle is still great. Then again, I come from an area where vehicles are a rusted mess by 10yrs/120K miles.


I am not sure what your standard is, but using 10 yr 120k miles as a standard in 2017 is pretty low. I understand you are from the rusty part of the country, but at least around here the standard is 20 years 200k miles, with no major mechanical issue.

 

[Lubener]

I will take the durability and the slight bump-shift feel anyday over a CVT.

 

[emg]

Originally Posted By: KrisZ
The nature of the CVT makes it inherently a weaker design than a traditional automatic transmission.


Compared to a 9/10/12-speed automatic? I wouldn't bet on that. Chrysler certainly seem to have had a lot of problems with their 9-speed auto, and neither will last long if the computer doesn't do its job properly.

So long as the US government keeps pushing 'fuel economy at any cost', transmissions will get more and more complex to try to achieve that.

Oddly enough, the only transmission that ever failed on any of my cars was a manual. Which cost about a third as much to rebuild as a new CVT does for our Forester.

 

[KrisZ]

Originally Posted By: emg
Originally Posted By: KrisZ
The nature of the CVT makes it inherently a weaker design than a traditional automatic transmission.


Compared to a 9/10/12-speed automatic? I wouldn't bet on that. Chrysler certainly seem to have had a lot of problems with their 9-speed auto, and neither will last long if the computer doesn't do its job properly.

So long as the US government keeps pushing 'fuel economy at any cost', transmissions will get more and more complex to try to achieve that.

Oddly enough, the only transmission that ever failed on any of my cars was a manual. Which cost about a third as much to rebuild as a new CVT does for our Forester.


When I said "inherently weaker design" I meant from an engineering point of view. What you mention about 9/10/12 speed automatics is the complexity, which is something different. Their design, however is still the same as 4/6/8 spd, and it is stronger than the CVT. Hence they can handle engines with lots of torque, where CVTs cannot.
Similarly, a solid axle is inherently a stronger design than a differential with CV axles. A leaf spring suspension is inherently stronger than a multi-link, double wishbone suspension.
It's called design trade-offs and I feel CVTs may not be at the point where their trade-offs are balanced yet. I have no doubt that in the future these transmission get a lot better, but they will never be a stronger design than a manual or traditional automatic.

 

[SteveSRT8]

Both CVT's and many-speed automatic transmissions can benefit from programming revisions.

As is typical in the auto industry some mfgrs get it quicker than others.

BMW has been lauded for their application of the ubiquitous ZF 8 speed, excellently programmed right out of the box.

My own Hemi RAM also uses the same design, it is flawless. Truly adds to the experience in a near magical way if you are a car nut, otherwise just a really good transmission.

Even the mighty Honda has had issues with the fwd/awd 9 speed ZF slushbox. Hopefully the aftermarket will continue to provide inexpensive aftermarket tunes for us...

 

[JTK]

^ That's the thing. What is it that actually goes when a CVT fails? I don't think I've ever seen or read of one failing catastrophically. I've never seen a broken belt or chain in one.

 

[SteveSRT8]

Originally Posted By: JTK
^ That's the thing. What is it that actually goes when a CVT fails? I don't think I've ever seen or read of one failing catastrophically. I've never seen a broken belt or chain in one.


As in any machine a careful mix of friction and lubrication/cooling is required. The way they fry the fluid is reminiscent of regular slushboxes. Actually overall they seem to be pretty reliable...

 

[emg]

Originally Posted By: KrisZ
Hence they can handle engines with lots of torque, where CVTs cannot.


They're designed to a spec, but that doesn't mean you can't build them to handle more. If I remember correctly, the Williams racing CVT was attached to a 750+ bhp engine, but I don't know what the torque output would have been. AFAIR the biggest problem they had was building an engine that could run at 15,000rpm for the duration of a race, not getting the CVT to handle the power coming out.

 

[stroked93]

So a couple weeks ago I commented on my nissan quest van in the shop for a remanufactured nissan trans. It made 700 miles and is out again. Fml

 

[JTK]

Originally Posted By: stroked93
So a couple weeks ago I commented on my nissan quest van in the shop for a remanufactured nissan trans. It made 700 miles and is out again. Fml


Any update on it?

 

[stroked93]

Still there 9th day dealership can't figure out why it's going into limp mode as there is no pressure drop present like before the replacement.

 

[LoneRanger]

Originally Posted By: SteveSRT8
Originally Posted By: Trav
Each to their own, your money you buy what you want. I wouldn't pay 10c for one if you gave me 9c change.


If it's the conical pulleys/belt style I am in complete agreement. Low torque capacity means the engine is programmed carefully to compensate for the transmission's shortcomings. Great for fuel economy, some work better than others. As with any slushbox, programming is the key to happy drivers.

But not in my driveway...


This is true as far as the way I understand Subaru has programmed the engine/CVT combo to work in their Forester in XT trim i.e. 2.0 liter direct injection intercooled twin scroll turbo boxer 4 cyl. Three driving modes I, S, and S# (Intelligent, Sport, and Sport Sharp). In I the programming is for fuel economy and the 2.0DIT provides it's 258 lb-ft of torque in a broad band reaching down to 2000 rpm, whereas in the S modes the CVT lets the engine rev to it's hp peak much higher in the range. Also has a manual mode simulating an auto-stick activated by putting floor shifter to the left and then using paddles on the wheel to step the CVT through eight "manual" simulated gears.

Apparently the CVT paired with the torque of the intercooled twin scroll along with the exceptional design of the Subaru AWD with the added "X-mode" makes it a pretty good little hill climber, basically only giving up the #1 off-roader spot in the CUV class to the Jeep Cherokee.

Looking into an XT to replace the '09 in my sig and this is what I've gathered, but any XT owners can tighten up the above.

 

[stroked93]

Got it back. Stoplight switch was sticking on. Causing the ecm to pull power

 

[JTK]

Originally Posted By: stroked93
Got it back. Stoplight switch was sticking on. Causing the ecm to pull power


Unreal that it took them NINE DAYS to figure that out, but it's great to hear you're back on the road. Some ATs, CVT or conventional won't allow much if any throttle if the brake is pressed, so I'm not surprised the energized brake light circuit caused this. Some won't rev in park or neutral even. That's why everything is E-throttle now. Easy to dummy proof from a keyboard.