DCT in cold weather

[the Ferret]

Didnt offend me, but I've read enough oil threads in the last 15 years, that I'm pretty sure I've heard or read it all ... I think.

The fact is, I cant remember an oil ( type..dino or synthetic as long as it meets the criteria listed above) related engine failure....ever. Use what makes you feel the most comfortable.

 

[bigbird]

Oil viscosity affects the shifting performance of the DCT. Oil with more stable viscosity (less thick when cold, less thin when hot) will provide more consistent operation.

Honda engineered the shifting algorithms to correspond to oil viscosity.
The PCM is programmed to read the oil temp form the oil temp sensor, and from that reading, apply the correct algorithm to the DCT.
By putting a different oil weight or type, eg a 10W-40 and/or a semi or full synthetic oil in the engine, that expected response form the DCT will not occur, as it will react differently to the unexpected oil.
So by using any oil other than GN4 10W-30, the owner can expect shifting patterns that Honda did not intend.
However, if one can find an oil that has the exact same specifications as GN4 10W-30, then that oil will behave the same as GN4, and the DCT would be perform as Honda designed it to.

 

[hulkss]

I had a lubrication related failure at high ambient temperatures (over 120 F in Needles, California) in an air/oil cooled motorcycle engine. After the ride, I was installing a camshaft and found the original roller followers and cam lobes to be "frosted". This is a well known failure mode caused by insufficient oil film thickness. I now use an oil that has, as Honda says about HP4S: "better high-heat performance, higher film strength".

 

[670cc]

I hate to say it but this is starting to look like the dreaded oil thread. We can leave the thread open but only for comments about cold weather DCT performance.

 

[hulkss]

Honda engineered the shifting algorithms to correspond to oil viscosity.
The PCM is programmed to read the oil temp form the oil temp sensor, and from that reading, apply the correct algorithm to the DCT.
By putting a different oil weight or type, eg a 10W-40 and/or a semi or full synthetic oil in the engine, that expected response form the DCT will not occur, as it will react differently to the unexpected oil.
So by using any oil other than GN4 10W-30, the owner can expect shifting patterns that Honda did not intend.
However, if one can find an oil that has the exact same specifications as GN4 10W-30, then that oil will behave the same as GN4, and the DCT would be perform as Honda designed it to.

I ran the DCT calibration (clutch learning) procedure as described in the service manual after switching to 10w-30 synthetic oil. It is my understanding that viscosity compensation is a part of the process as it calibrates hydraulic pressures that are influenced by viscosity.

Synthetic oil has a more stable viscosity within the specified range, hence offering more consistent performance. See section 5.2 and 5.7 of the attached document.

 

[Deleted member 1183]

Maybe the 2021's will allow/recommend the new Honda Synthetic....they spent that research time, effort and money for some reason. It seems a lot of new bikes are using synthetic for the reasons mentioned in the Honda release.

Perhaps on their high performance bikes. I once mentioned the possibility of using a full synthetic in my NC to the importers here. They very firmly told me not to. Either way I have been using two brands (Bardahl and Eurol) of 10/40 semi synthetic oil in most of my bikes for years. I have never had an oil related issue. The only bikes that I used full synthetic in were my former KTM's because they specified them.

 

[MZ5]

It is my understanding that viscosity compensation is a part of the process.

See section 5.2 and 5.7 of the attached document.

Correct; viscosity compensation is part of the control system.

 

[dduelin]

The feedback loop built into the DCT does account for variations in viscosity due to temperature and shear-down. Therefore it makes no difference in performance to use synthetic or dino oils as long as specified 10w30 or 10w40 oils are in use. The paper and the service manual dictate the clutch initialization procedure be done when parts are replaced not when oil is changed. The feedback loop accounts for oil performance variations.

 

[dduelin]

Perhaps on their high performance bikes. I once mentioned the possibility of using a full synthetic in my NC to the importers here. They very firmly told me not to. Either way I have been using two brands (Bardahl and Eurol) of 10/40 semi synthetic oil in most of my bikes for years. I have never had an oil related issue. The only bikes that I used full synthetic in were my former KTM's because they specified them.

Honda is clear on this and likely due to research conducted with vendor/partner Idemitsu in the mid 2000s. I got to read the white paper when I was authorized to purchase Honda oils but had to indicate non-disclosure or copying for personal use. After that research Honda changed liquid cooled street bike recommendations to 10w30 GN4 because it produced lowest cylinder head and valve train temperatures and heat from frictional losses yet met requirements for protection across oil change intervals.

 

[hulkss]

I do believe that the clutch initialization procedure compensates for mechanical component manufacturing tolerances as encountered when replacing parts. I believe the same thing goes for worn components like clutch plates and shifter components that are altered dimensionally from wear. So I do the procedure after oil changes. It's very easy and I don't think there is any downside to it. I consider it a transmission tune-up.

 

[lowrider]

I do believe that the clutch initialization procedure compensates for mechanical component manufacturing tolerances as encountered when replacing parts. I believe the same thing goes for worn components like clutch plates and shifter components that are altered dimensionally from wear. So I do the procedure after oil changes. It's very easy and I don't think there is any downside to it. I consider it a transmission tune-up.

Oil change timing is an easy to remember interval. I wonder if there have been any studies on component wear/failure. Other than brake pads I've never had anything wear our or "fail" on a Honda except an A/C compressor clutch on my CRV at 186K.

 

[dduelin]

Oil change timing is an easy to remember interval. I wonder if there have been any studies on component wear/failure. Other than brake pads I've never had anything wear our or "fail" on a Honda except an A/C compressor clutch on my CRV at 186K.

Honda R & D likely service-cycled multiple prototypes and multiple production spec DCTs to component failure. Not once but many times.

 

[hulkss]

Oil change timing is an easy to remember interval. I wonder if there have been any studies on component wear/failure. Other than brake pads I've never had anything wear our or "fail" on a Honda except an A/C compressor clutch on my CRV at 186K.

The DCT is a long life reliable system. The most likely way to hurt a DCT is by riders using the throttle to hold their position on a hill when stopped. This can overheat the clutch and cause damage. Let the bike idle and use your brakes.

 

[670cc]

I do believe that the clutch initialization procedure compensates for mechanical component manufacturing tolerances as encountered when replacing parts. I believe the same thing goes for worn components like clutch plates and shifter components that are altered dimensionally from wear. So I do the procedure after oil changes. It's very easy and I don't think there is any downside to it. I consider it a transmission tune-up.

As an outsider looking in (not being a DCT owner), I find it surprisingly unconventional for a modern vehicle to need or benefit from a transmission tune up or calibration/initialization at such frequent intervals as every oil change. Such a thing would likely not be tolerated with automic transmissions in the modern automobile world. (I’ve never had to initialize or calibrate an automatic transmission in a car, and I’ve driven cars, vans, truck over a million miles). Motorcycles are inherently high maintenance vehicles compared to automobiles, and motorcycle owners are probably more likely to tolerate or even get satisfaction from tinkering with the Honda DCT. However it seems like Honda should have automated this initialization routine so as to be done behind the scenes, or designed a way to continuously update the transmission to account for wear without any operator intervention.

 

[dduelin]

As an outsider looking in (not being a DCT owner), I find it surprisingly unconventional for a modern vehicle to need or benefit from a transmission tune up or calibration/initialization at such frequent intervals as every oil change. Such a thing would likely not be tolerated with automic transmissions in the modern automobile world. (I’ve never had to initialize or calibrate an automatic transmission in a car, and I’ve driven cars, vans, truck over a million miles). Motorcycles are inherently high maintenance vehicles compared to automobiles, and motorcycle owners are probably more likely to tolerate or even get satisfaction from tinkering with the Honda DCT. However it seems like Honda should have automated this initialization routine so as to be done behind the scenes, or designed a way to continuously update the transmission to account for wear without any operator intervention.

FWIW Honda doesn't mention it as any kind of recurring maintenance item but only necessary when major components are replaced. Clutch plate wear is automatically compensated for in the design and the initialization procedure isn't intended for that anyway. I agree and think it is unnecessary at anything approaching OCI but since it doesn't hurt anything and makes the owner feel better, what's the harm?

 

[TacomaJD]

I fail to understand why people always overthink the oil thing. It's just as simple to put oem filter and Honda GN4 oil in the bike as it is any other oil and filter. AND they recommend 8k mile oil change intervals on said GN4 oil, which is great for conventional oil. But somehow, most folks seem to know more than the Honda engineers and think different oils are better or provide some sort of an edge. You're on an NC....not a built race bike. And the DCT shouldn't work any differently in weather temps compared to the manual version, unless maybe the shift control motor reacts slower in cold weather or something, but that wouldn't have anything to do with the oil or the transmission itself.

 

[670cc]

FWIW Honda doesn't mention it as any kind of recurring maintenance item but only necessary when major components are replaced. Clutch plate wear is automatically compensated for in the design and the initialization procedure isn't intended for that anyway. I agree and think it is unnecessary at anything approaching OCI but since it doesn't hurt anything and makes the owner feel better, what's the harm?

You're right, Dave. Some owners take it upon themselves to do this clutch initialization task as Honda does not list it in the normal maintenance schedule. Like I said, I guess motorcycle owners just like to tinker. My point was that I'm surprised Honda didn't design the DCT to totally automate the routine so it wouldn't even involve operator intervention. For example, even when a new clutch pack was installed, the design would automatically compensate for the new components.

 

[dduelin]

At least it does away with clutch cable adjustments and nary a glazed clutch pack from operator error

 

[670cc]

At least it does away with clutch cable adjustments and nary a glazed clutch pack from operator error

True. Too bad Honda didn't spend a little more and put a hydraulic actuator on the NC manual clutch. Other than fluid changes, my Goldwing manual clutch has required zero maintenance. Oh well, back to DCT cold weather talk.

 

[hulkss]

I fail to understand why people always overthink the oil thing. It's just as simple to put oem filter and Honda GN4 oil in the bike as it is any other oil and filter. AND they recommend 8k mile oil change intervals on said GN4 oil, which is great for conventional oil. But somehow, most folks seem to know more than the Honda engineers and think different oils are better or provide some sort of an edge. You're on an NC....not a built race bike. And the DCT shouldn't work any differently in weather temps compared to the manual version, unless maybe the shift control motor reacts slower in cold weather or something, but that wouldn't have anything to do with the oil or the transmission itself.

I tend to do a little more than the minimum required per the service manual. For example I'll change the clutch and engine oil filters every time I change oil even though the manual says you can go 16,000 miles on them. Cleaner oil strongly correlates with reduced engine wear. The DCT is much different than the manual transmission and I have found that it does respond to the clutch learning procedure and oil selection.