[Solved] Honda DCT Experiences
I’m curious if anyone has any experience with Honda DCT? The one I am speaking of is found in many Acura ILX, for example.
I am of the understanding that it is not your traditional clunky DCT at lower speeds. Because it has a torque converter instead of the actual clutch.
How is the reliability? How is the performance? How is the maintenance? What are its quirks?
experience with Honda DCT
Well although I do not have much first hand experience with Hondas DCT - I was interested in them and have done a lot of research.
Generally, These are hydraulically controlled wet dual clutch transmissions, and they have the same issues as most transmissions in this segment.
The clutch pack, suspended in the oil bath, wears and all of the friction materials generated from it get into the oil - on these, like on many early 2010s DCTs, that's the same oil that's pumped through (and used by) the sensitive hydraulic control mechanism (valve body and solenoids) and as such they get worn out and fail.
Reading into owner experiences really shows that most people (the absolute majority) is experiencing issues with shift quality, this poll on a form of Acura TLX owners reveals that 76.5% reported some kind of shifting issues - and from experience, I'm almost certain that the other 23.5% probably have the same issues but are oblivious to them.
And lots of others, looking through websites of eastern European transmissions shops (where labor costs very little and there are plenty of engineers willing to do manual labor), people claim "torque convertor wear", "heat exchanger tends to get clogged", "clutch overheats even with just a very little bit of spirited driving", "clutch requires replacement at just 50% wear"
And it seems to be just poor quality, I found a lot of other different issues people have had with them
And lots of threads of just jerkiness.
traditional clunky DCT at lower speeds
Honestly? Driving a Renault EDC and a dry DSG - pretty dated cheap dual clutches, other than a bit of light vibration during the very initial part of the launch, both felt more refined than most conventional automatics.
The issue is RELIABILITY - these do require repair, and cost $,$$$ to keep in the long run.
But I still honestly would just recommend getting a conventional automatic, nothing drives and feels like it.
I've had automated cars, dry DCT, wet DCT, and there's just nothing like a calm and collected "slip and slide" boring auto!
the torque converter in the DCT (...) Seemed like a brilliant solution on paper
Being honest, I think that the addition of the torque convertor is really what made this transmission not viable -
Good DCTs delay spark during shifts (this causes that iconic exhaust sound, "The DSG fart"), this means that for an instant the engine is not producing much additional torque - This allows the transmission to shift as if there's no engine torque or rpm discrepancy to worry about.
With a torque convertor, this is not possible, as the torque is transmitted through liquid flow between the components of the torque convertor and it can't just "stop" on command.
Additionally, DCTs are usually purchased from efficiency and with both a torque convertor and wet dual clutch - this pretty much universally means they've lost all benefits and perhaps made it worse (as both of these mechanisms are very inefficient)
This is not Honda's first automatic gearbox that's based on a manual, the Accord 5 speed automatic that has been causing quite a few issues (but overall decent, much better than this TDCT crap) is actually not a planetary automatic - but actually uses internals similar to manual transmission but has a torque convertor instead of a clutch and clutch packs instead of synchronizers, sleaves and forks.
That one was decent shifting but was overall just slightly worse than Toyotas conventional planetary automatic.
Also, There was a study conducted by GM which showed that a torque convertor is pretty useless.
They tried to see if it ever would make sense in a DCT, they've set out the goal of creating a transmission where "the clutches would not slip" (as in all of the rpm matching would be carried out by the torque convertor and it's clutch)
What GM has found that this proposed super efficient smooth 7 speed gearbox, would in theory result in a "0.25% increase in fuel economy" (over a dry clutch dual clutch transmission, the kind you'd find in a Smart or a Focus) and "1 and 2 percent" "Compared to a six-speed planetary automatic"
In other words, GM's research has concluded that the best dual clutch, is a 6 speed automatic - to me it feels that a Toyota 8 speed would be more efficient and quicker shifting than their proposed TDCT.
I do wonder if more frequent transmission oil changes would alleviate or significantly postpone the problems
More frequent oil changes will help prevent torque convertor issues, postpone the heat exchanger and valve body contamination.
But overall, the clutches are still going to get worn out from having to engage and disengage underload.
Also being an early-mid 2010s dual clutch, I think they began shipping these on the 2014 model year - chances are is that no matter what it's going to be jerky, that's they way that those were.
Thanks again for your detailed insight.
That’s funny about the best DCT being an automatic.
Thanks for the detailed information.
When I learned about the torque converter in the DCT, it got me intrigued. Seemed like a brilliant solution on paper. But real world, with your descriptions, seems like the reliability might be an issue.
I do wonder if more frequent transmission oil changes would alleviate or significantly postpone the problems, similar to CVT’s.