Odd that I've never read anything about this anywhere before. You have any reports to cite that, or is that op-ed?



One would have expected that Consumer Reports (at least) would have picked up this at some point in their reviews of the cars, instead of constantly giving the Hondas such excellent marks.

 

In a simple CVT you have a idler pully taking up slack. It will work of the backside of the acuator for the varible pulley so everything stays constant.

 

I owned a Justy. Ive done alot of work with CVTs in laths and machine tool applications. Convyer systems. Matrial handeling systems. Blower and airhandler systems. There was a time in the industrial world when they where seen as a great thing!!! Not anymore. Im glad there fadeing out of use and VFD's are takeing the rightful place.

I just hate to see folks have trouble with them. I got rid of the CVT driven lathe in my shop at work. If I ever have one in my life again at any level it will not last but as long as it takes for me to run from it.

 

I believe that essentially, that is what is happening. I have seen diagrams of the Honda CVTs and from what I understand, they have a computer-controlled clutch that kicks in at low speeds. In the HCH-1 at least, I can feel going into auto-stop, the car starts to glide a bit with very light brake pressure (the clutch releasing).

If I, say, stop at a stop sign, it begins to auto-stop, then I give it a lot of gas for some reason (say I'm going up a hill, or want to turn onto a busy road or something), sometimes the engine will rev a bit before the clutch syncs, exactly the same as revving in N and dumping into D. If you give it very light gas, or say, coming out of a red light, release the brake early and let the engine idle for a moment, the tranny should engage fully with no problem.

Honda's CVT I know has two variable pulleys, here is a page describing the CVT in the Insight which I presume is the same as the one in the Civic.

The Toyota CVT is actually a fixed-gear-ratio transmission using planetary gears as a differential to split engine power between the drive wheels, and a generator, which directly powers a second motor (in addition to some power coming from the battery as well). This produces a blend of the engine's torque at high RPMS and the motor's torque at low RPM. By varying this ratio, they get a CVT-like effect without actually any mechanical shifting. Ideally this transmission should have the least amount of problems, but the drawback is the inefficiency in the conversion from mechanical to electric power and back. This eCVT (iirc electric CVT) should also scale to work for just about any size motor as well, provided the electric motors are also scaled correctly.

 

Yes this happens to me still. This seems like a normal occurrence, when the car thinks it should be disengaged and you step on the gas it takes a sec to get back in gear so to speak. However, I have experienced similar effects at times when it doesn't seem like the tranny should be disengaged, like pulling in the driveway or around a corner. It happened several times within a week or two at times that didn't seem quite right, so it made me wonder. But now that seems to have stopped and it only does it in situations where it seems appropriate, my concern has waned.

I think it must have just been a microprocessor confused momentarily... those things are only as good as the programmer, who usually can't think of everything. :-)