Pulsating Droning noise, sounds like bearing

That's right.

But to be fair most of the time i drive in EV and econ mode , it's only running the engine on long highway trips and then i use cruise control and don't accelerate fast.
 
(it looks to me like the whole thing, atkinson engine plus generator plus traction motor is one assembly with the electric motor/generator connected in line with the ICE crankshaft)

They ordered just the transmission which is labeled repeatedly as "transmission (e-CVT)" on all the docs they've shown me. He also showed me what he'd be doing to install the new one and it decouples at the engine where there is a flywheel which I believe is also getting replaced.

I'm very ready to have my Clarity back. The 2018 Accord Sport they've loaned me is very much NOT a Clarity in comfort.
 
Understood and I wish you all the best resolution. Selfishly I’m seeing this as a learning opportunity. I consider myself much a mechanical car expert, but I’m admittedly a bit confused on some things about how this car works, especially from a “transmission” perspective, what the heck they’re actually doing to yours to fix it, etc....

When it’s all said and done I’d LOVE to see the final warranty service ticket which will shed a whole bunch of light on what’s going on!

More importantly you need your dang car fixed!! And I totally respect and empathize with that...
 
@tterag, I too am sorry you have had to go through this. Thank you for such diligence in letting us know about your situation. It very well may help someone else to diagnose this if it crops up again. I sincerely hope that this fixes your issues for good and that you get the car back soon. Best Wishes.
 
I’m admittedly a bit confused on some things about how this car works, especially from a “transmission” perspective
Car & Driver came up with a great explanation back when Honda first unveiled their i-MMD replacement for IMA. I like telling people there are no belts under the hood of my Clarity PHEV, not even in the eCVT transmission.
 
Here’s the parts diagram and part number. No price for the transmission. The engine block and head are about $2500-$2800 each. The transmission in my Civic hybrid, which was a full CVT, was a $5500 part when it failed.

https://www.hondapartsnow.com/genuine/honda~0~20041-5wl-a00.html

That is very interesting...and digging deeper that unit is the exact same shape as the “flywheel case” in this section which shows some of the components in and about it...
https://www.hondapartsnow.com/parts...rng-clarity-phev-ka-cvt/at-flywheel-case.html

And yet further digging into “clutch”, “differential”, etc reveal additional parts without cases. So I am starting to assume many of those such parts itemized out are all within this same Flywheel case, and as a whole Honda is calling thar fully loaded flywheel case a ecvt. Possibly not available/discontinued as an assembly for parts counter purchase because Honda is protecting their technology from the competition’s prying eyes, but obviously Honda can send a whole assembly to one of their own dealers for warranty repair.

With supposedly 4 sets of gearsets within, I can easily see how one that was assembled with one gear lash shimmed slightly off, one gear or bearing with a flat spot or rough tooth or other slight manufacturing flaw, or whatever, would easily cause the described problem. I’ve rebuilt old school rear differentials several times and they can do some strange harmonic whining at different speeds if done ever so slightly out of perfection....

Lots of assumptions, but until I have an opportunity to see one of these drivetrains disassembled all over a shop floor and workbench, which will likely never happen since I’m out of that scene forever, my assumptions will have to suffice.

And Insightman, that was a good read...I had not seen it before. Thanks! Some pieces are coming together...it’s largely a terminology thing.
 
Last edited:
My car has just under 16,000 miles on it. This morning on the way to the office I heard a noise which seems similar to this. Going to go visit the dealer tomorrow and have them listen. Hope to print the applicable posts here to take to them. This is the first problem I have experienced with this car.
 
Took my car to the dealer yesterday. Tech guy rode around with me and agreed that there is a noise that is not supposed to be there. He thinks it is the right wheel bearing. Taking the car in on Sept 16 so they can do some diagnostic work. @tterag, have you had the eCVT replaced yet?
 
Give this a try.

Remove the plastic wheel covers and see if the noise goes away. I noticed when I was cleaning the car this morning that they move when I clean them. Makes me wonder of they resonate at certain speeds if not on tight.
 
Checked my wheel covers. They seem to be tight. Have appointment this Monday (9/16). Will give update. I really don't expect the problem to be resolved on Monday.
 
I have been to the dealer 3 times. The first a ride with the head mechanic - he agreed that the noise was in the drive chain and most likely a wheel bearing. The second visit, they put the car on a lift and diagnosed the problem as a wheel bearing. The third visit they replace the right wheel bearing. Noise was still there. I have an appointment tomorrow to replace the left wheel bearing and an 'inner' bearing. Will post back the results.
 
I have been to the dealer 3 times. The first a ride with the head mechanic - he agreed that the noise was in the drive chain and most likely a wheel bearing. The second visit, they put the car on a lift and diagnosed the problem as a wheel bearing. The third visit they replace the right wheel bearing. Noise was still there. I have an appointment tomorrow to replace the left wheel bearing and an 'inner' bearing. Will post back the results.
Find out what the “ inner bearing” is. The parts diagrams show only a half shaft bearing, in addition to the wheel bearing. If they are replacing that, I’d be surprised if they don’t just install a new half shaft.
 
Car is fixed! Last week the dealer replaced the right wheel bearing with no change in the noise. Today they replaced the left wheel bearing and noise is gone! Guess that is why the write 'YES' and 'NO' on your knees when they are doing a knee replacement.
 
Thanks for reporting back. Bummer it took so many trips. I fear all these wheel bearing replacements will lead to reliability questions.
 
@Groves Cooke... That's the same reason why my friend replaced both knees at the same time :) THis does bother me that the bearing went out so quickly. I had cars that lasted over 10 years and 100k without any bearing issue. I had German cars and we all know they don't last ! I hope this is not a design or defect.
 
I have a 2018 with 17k miles. I'm noticing an annoying harmonic droning coming from the front of the car. It is very noticeable on smooth roads at lower speeds (25-40) and very pronounced at highway speeds. It can be felt in the steering wheel and floorboards lightly.

Doesn't matter which mode the car is in or if the ICE is running or not.

Best onomatopoeia I can offer is: waaaaaoooohhmmm waaaaoooohhmmmm

The frequency of the noise is affected by speed but not by as high a ratio as I would expect if it were wheel related. The frequency increases with speed, but disproportionate to the speed of tire rotation. Trying to find a way to say it that makes sense. Not sure I'm winning.

Took it to the dealer and went for a ride with the tech. He heard it and reported it to whatever tech gods they send stuff off to and are waiting for a reply.

Any thoughts?
I had the same problem with my 2018 Clarity with 10,800 miles. Took it in yesterday, Tech heard the noise replaced both the wheel bearing and the wheel hub. Problem is resolved. They decided to do the hub too since the bearing was bad and felt it could have damaged the hub. Under warranty, the fix was about $450.00. I am happy with the result so far. They told me that the wheel assembly could have been damaged in transit!!!!
 
Back
Top