DCT shift motor failure

Helix

New Member
On 9/14/19 I related a DCT problem on my 2016 NC700XD with 36,000 miles. It was stuck in 2nd gear and wouldn’t start. I finally got it back in neutral and functioning normally after lots of fiddling but my concern at that time was that I didn’t know for sure what had caused the problem and how to avoid it in the future.

On 12/26/19 at 38,500 miles it happened again with me limping home in who knows what gear (none displayed) and once again finally getting it back in what looked like normal function again. The next day I took another ride and everything worked fine until I stopped after about a one hour ride. Upon restarting and riding ~100’ gear position showed no gear but “-“ fast blinking. Thinking I could fix that using the same procedures as before I stopped and turned it off. Bad decision. It wouldn’t do anything at all. Called my roadside assistance and was towed to the Honda dealer.

Since this dealer has zero experience with the NC700XD they called Honda Tech and were told that they are seeing high mileage bikes with a loose Star Bolt causing similar problems (as mentioned in other posts). They were told to remove and replace the bolt after applying locktite. My shop manual says it’s supposed to be locktited but for some reason Honda didn’t do that on some or all, I don’t know which. Mine was not loose and did not have locktite on it, but it does now. So that wasn’t the problem. While in there, I asked them to check the clutch pack for wear and they reported all looked very good.

Dealer was then told by Honda to replace the shift motor which they did. They buttoned it up and it still displayed D+S but it functioned like normal and I could switch between D & S so I went through the calibration process with the side stand up and starting while holding the brake to finally get it back to normal function. I’ve now ridden it about 350 miles and hope the problem is solved since I’ve had no malfunctions.

Feedback from the Honda Dealer was that the shift motor had an open short. They said the motor over heats causing the motor to fail. Why the motor overheated was not explained. Often I do ride in D using frequent downshifts with the paddle shifter while exiting a curve or going up an incline. Other times I’ll be in S2 and let it do all the shifting, but I don’t think I do anything to overtax the shift motor.

So, I do admit to having my confidence in the DCT shaken but it does seem to be fixed and I hope to ride many more miles on this bike. I’m now 79 and really like the ability of not having to use a clutch/foot shift and I particularly like the different modes to change the character of the bike.

Ride aware and in the moment.
Helix
 

670cc

Super Moderator
Staff member
Super Mods
Site Supporter
With our new forum software, I can’t easily link old threads, but we had a case here about a year ago where a shift motor went bad. The dealer apparently had little experience servicing the DCT, and much time was spent and many parts swapped before a new shift motor was installed and the problem was solved.

I laugh at the failure description given by the Honda dealer in your case. Regarding electrical things, open and short circuits are opposite conditions. An open short is not possible. It’s like sayIng you have an open closed door, or a dry wet towel.

The DCT is obviously more complex than a manual transmission, so there are potentially more things to go wrong.
 
Last edited:

TacomaJD

Member
If shifting manually is what could overheat the shift motor, I suppose mine will soon burn out as much as I shift while on track or riding twisty roads. But hopefully that's not the underlying cause of the motor overheating.
 

670cc

Super Moderator
Staff member
Super Mods
Site Supporter
If shifting manually is what could overheat the shift motor, I suppose mine will soon burn out as much as I shift while on track or riding twisty roads. But hopefully that's not the underlying cause of the motor overheating.
If it's possible to overheat the shift motor by shifting manually, then Honda failed in their design and needs to go back to the drawing board.
 

Helix

New Member
After your comments pointing out my incorrect description of the state of the shift motor I talked to the lead mechanic (he didn’t make the comment) at the dealership who was directly involved in talking to Honda and asked him how he knew the shift motor was bad and should be changed. He said Honda made several suggestions as to where to look. He also said the error codes on my bike pointed to several possible places to look but they all had one thing in common; the shift motor. There is nothing rebuildable on the shift motor so they replaced it.

As to the “open short” description, I may have misunderstood what was said since I talked to several people. Maybe they meant it shorted and became open. What he was trying to communicate was that the shift motor was dead. They seem convinced that the motor had been overheated by hard use over a long period. I didn’t see the motor so I can’t elaborate but they did make comments several times about the brushes.

I do ride for extended periods on curvy roads with lots of shifts from 2nd to 5th but I doubt that’s any different than most of you. I’m hoping I just had a weak shift motor and I won’t have to worry about it again.

Helix
 

davidc83

Site Supporter
Sounds like it was just sift motor which failed....anything made by man can go bad at any time...Some on this board has had oem batteries go bad in a year and some are still using 6, 7, 8 year old batteries; some have 8 year old bikes with stock headlights, while I am on my 3rd headlight on my 7 year old bike...it just happens.
 

dduelin

Site Supporter
With our new forum software, I can’t easily link old threads, but we had a case here about a year ago where a shift motor went bad. The dealer apparently had little experience servicing the DCT, and much time was spent and many parts swapped before a new shift motor was installed and the problem was solved.

I laugh at the failure description given by the Honda dealer in your case. Regarding electrical things, open and short circuits are opposite conditions. An open short is not possible. It’s like sayIng you have an open closed door, or a dry wet towel.

The DCT is obviously more complex than a manual transmission, so there are potentially more things to go wrong.
Who knows if that is what the dealer actually said and the OP heard but it is certainly what the OP typed.
 
Top