Anyone still here in late 2025 with a 2006 HCH II on the road?? I finally changed my 2006 HCH II CVT inline filter, and cut open the original factory filter to see what it looks like inside. I've never seen a teardown of the HCH II CVT filter before.

This is ~20 years old but only 93000 miles. I don't drive this car a lot. For the last 6 months/2000 miles, my CVT has developed a loud whine noise in D/S/L although completely silent in all other shift including R. The CVT drives smoothly with no hesitation, slipping or any other shifting problems except the whining noise. I made a mental note to change the CVT fluid at my next Maintenance-Minder oil change.

So, this month, I changed the oil and also did a CVT drain/fill 2 times with 50 miles of driving in between. 2 drain/files is not a complete flush but close enough. Of course I am only using the now-old-generation Honda CVT fluid; the Honda dealer checked my model year since I was buying the old generation CVT fluid that isn't used in any of their modern vehicles. The CVT fluid change didn't improve the noise so I thought *maybe* the filter was partially clogged and I changed that too. I had actually purchased the filter in 2015 but didn't bother to install it until today in 2025. I am a master procrastinator.

Anyway I don't think it was clogged although it's very dirty. At this millage, the filter medium is completely black. I'm guessing it started yellow or white. I don't know if a dirty filter has any impact on the shift quality. I do't have any change in shift behavior or CVT noise before/after filter change. To cure the noise, the only other home-remedy I could try without fully disassembling the transmission is to drop the CVT pan and clean all the parts inside. But... it drives silky smooth and it's 20 years old, and the CVT noice is not that much worse than the "CVT drone" I hear with other CVT cars... So I am inclined to leave it alone for now. Or trade it in for a Prius!

Meanwhile, I thought the forum might enjoy some pictures.


I cut it with a hacksaw. I believe the side I cut is the output side.



The plate was perfectly flat but I bent it trying to pry it off. It was held in place with glue on pleats.



HCH-II CVT Filter cut open


This hole is completely open on the intake side, you can see straight through to my red screwdriver handle. The pleats were damaged as I pried the plate, not before.




This spring is probably a bypass, but it's actually a very stiff spring.



Here, I am forcing the spring to open.


inside with some pleats town off.



the pleats are completely black. I am sure this is all wear and tear from the CVT, since the fluid doesn't start black.

 

Thanks for this. I got a 2006 HCH2 too with 220k and I'm unsure if the cvt fluid/filter has ever been changed. I plan on doing it soon too. Where about was the filter located? I've been under mine a number of times for oil changes & know where the cvt fluid drain plug is. But i dont think i've ever seen a filter down there.

Also do you know if there is a better fluid out there for it than the honda stuff?

 

The filter is inline between the transmission and radiator, so look under the radiator.

I am still using the Honda fluid but I’m slightly tempted to try something else because my CVT is still making a loud whining noise even after replacing the filter and also replacing fluid twice.

After my initial post I also dropped the transmission pan and replaced the internal “strainer” too. The pan needed a heat gun and gasket separator to break the 20 year old gasket. Some bolts require a wobble socket.

 

how much fluid came out when you dropped the transmission pan?

 

About 5qt, but hard to say because it drips everywhere when you drop the pan, even if you already drained it through the drain plug. Anyway I used 5 whole (Honda CVT qt) bottles and a little bit of the 6th bottle to refill it after I was done.

 

Thanks bro!