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TheEnglishman

DCT stuck in gear - can't select neutral - SOLVED

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TheEnglishman

 

So I got to the gates at work today and something happened whereby the bike wasn't in neutral and wouldn't select any gears.  Or display what gear it thought it was in. And it wouldn't start

 

I pushed it to a parking space and had a google.  A clutch reset didn't do anything.  The bike wouldn't start.  Nothing wrong with the battery. It showed it was in 5th.  Turning on the ignition had the engine making a slow (half second) clicking sound for maybe 5 seconds - possibly a solenoid trying to find a neutral? 

 

Resolved by pushing the bike slowly backwards while it was clicking.  5th, 3rd, 2nd, neutral!   It had to be clicking though - so move it backwards immediately after turning on the ignition.  

 

Yay!!

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Beesto

Hi Neil,

I encountered the same problem with my brand new bike a couple of weeks ago - see post below. 

Not had any issues since (although still only covered 120 miles), but I thought it was strange. Eventually, by moving it i got it back to neutral.

 

 

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embee

Remember that the gearboxes in bikes have fairly large dogs (arrowed), and if they don't line up with the slots it won't be able to shift from one gear to another. If the shafts are turning (engine running) then they'll usually slot in OK, if the engine is stopped and the bike isn't moving then they can baulk by hitting the top of the drive segment and that's that. If you turn the wheel the output shaft will turn which will allow them to slot into place.

The gear pairs stay in mesh all the time, you can see that all the gear pairs in the picture are in mesh, the actual ratio in use is selected by moving pairs of gears along splined shafts to engage the dogs with the driving element. The gear teeth don't go in/out of mesh at any time, it's just the relevant dogs which go into the slots to provide the drive..

Rj0UQDtMy94red.jpg.02a5d7eb2ebdd286085279c3f61ba2b5.jpg

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elbee
24 minutes ago, embee said:

if they don't line up with the slots it won't be able to shift from one gear to another.

 

Interesting. Getting stuck in 5th - unlike Anthony's stall at 50mph, Neil's bike had presumably dropped down through the gears until he stopped at the work  gates but then showed 5th gear? Weird!

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SteveThackery

As Murray says, having to shuffle the bike back and forth to get it to change back down through the gears is completely normal on all bikes, whether DCT or manual (except CVT, of course).

 

The mystery is why the bike ended up stationary in 5th gear, and that is what we need to investigate.  

 

I wonder if Neil (and possibly Anthony) caught the handlebar stop switch while in motion.  Is any DCT owner willing to try it on their bike?  If we can get a definitive answer as to whether the DCT changes down as the bike comes to a halt, or stays in whatever gear it was in, it would help us diagnose issues like this enormously.

 

(I'd be happy to do it myself, but I've traded my NC.  :ermm:)

 

--------------------------------------------------------

To be specific, my suggested test would be to put the bike in 'D', drive along at 30mph in a safe area, and then operate the red Stop switch on the handlebar.  

 

1/ Observe the instrument display as the bike decelerates to a halt.  What is indicated?

 

2/ Listen for the gearbox changing down (or not) as the bike slows.

 

3/ When the switch is put back in the Run position, what does the display show?  Is the bike in gear or neutral?

 

Is anyone willing to do this for us?

 

 

Edited by SteveThackery

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TheEnglishman

Did it again today on the way to work - stuck in 5th while moving.  Stopping, cycling ignition, waiting for clicks and slowly moving backwards resolved it (again)

 

It's going to be the clutch, right?  If the gears won't disengage while moving I can't see it's anything but the clutch.  Although just exactly how a dual clutch box works is beyond me.

 

I don't have any engine diagnostic software to look at codes so it's off for an expensive trip to the dealers next week :-(

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TheEnglishman
4 minutes ago, SteveThackery said:

...

I wonder if Neil (and possibly Anthony) caught the handlebar stop switch while in motion.  Is any DCT owner willing to try it on their bike?  If we can get a definitive answer as to whether the DCT changes down as the bike comes to a halt, or stays in whatever gear it was in, it would help us diagnose issues like this enormously.

...

 

Might be the side stand switch.  Far more likely, especially as there's not salt been on the roads.  Will investigate.  Dunno quite why the problem would manifest itself while the engine was running though.

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SteveThackery
6 minutes ago, TheEnglishman said:

Did it again today on the way to work - stuck in 5th while moving.  Stopping, cycling ignition, waiting for clicks and slowly moving backwards resolved it (again)

 

Really sorry to hear that, mate.  Might end up as a return to the dealer, then.  

 

6 minutes ago, TheEnglishman said:

 

It's going to be the clutch, right?  If the gears won't disengage while moving I can't see it's anything but the clutch.  Although just exactly how a dual clutch box works is beyond me.

 

It could be many things.  A clutch not disengaging, the shift motor not working...  Could be mechanical, could be electrical.  Do some googling on DCT gearboxes - there's plenty of detailed information out there.  Also, search around this forum because DCT problems have been discussed in the past and you will find some informative discussions.

 

Unfortunately it's bloody difficult to diagnose such faults by remote control.  You need someone with a good technical understanding of how the DCT works, and how to use a multimeter, to look at the bike.

7 minutes ago, TheEnglishman said:

 

Might be the side stand switch.  Far more likely, especially as there's not salt been on the roads.  Will investigate.  Dunno quite why the problem would manifest itself while the engine was running though.

 

Yeah, might be, but it could be all sorts of things.  Well worth having a good look, though.

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pjm

Did the bike stall or cut out again or just get stuck in gear?

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embee

The engine won't crank/start if it is in gear. It has to be in neutral before it will start. As long as it will start once in neutral then that side of things is OK. The problem seems to be why it isn't shifting gear.

 

There was a thread very recently from a member in the USA with similar issues who went through a series of frustrating visits to their dealership who tried all sorts of replacement of parts in a shotgun approach, rather than carefully assessing the actual fault behaviour. That turned out to be a faulty shift motor. Sounds to me like it could also possibly be the case here.

 

First thing would be check the connector on the shift motor itself. Unplug, spray with WD40 or ACF50 or contact cleaner, push on/off a few times and see if it still happens. If it does still happen, what you really need to do then would be remove the shift motor (very easy, a couple of bolts item 11 and it lifts out) and then check that the motor actually runs in both directions by applying 12V to the contacts, reversing the polarity will reverse the direction. It should kick quite strongly, if it is lethargic it could be faulty, though they are proving to be pretty reliable but of course anything can fail.

 

https://www.bike-parts-honda.com/honda-motorcycle/750-MOTO/NC/2015/NC750XDE/Engine/REDUCTION-CASE/71541/E_19/1/25744

REDUCTION-CASE-Honda-MOTO-750-NC-2015-NC750XDE-E_19.jpg.83a00435861b6f302af8397b34a0172f.jpg

 

Edit - if you did need a shift motor, they do come up on the auction site, albeit at rather silly money, but not as silly as Honda new price. See item number 142061166774 for example. The 700 and 750 uses the same motor, and from what kayz1 said in another thread they are used on other things too. See the list of uses here https://www.bike-parts-honda.com/honda-motorcycle/assignment_spare_parts/31300KVZ631

You could search for examples on the auction site for some of these other applications.

Edited by embee
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kayz1

Yes we all think this DCT box is new, not so they are and have been used in farm Quads for a number of years before they put them in bikes..

So the info on them should be around some dealers ( rural anyway ) The way my dealer told me to test the strength of the motor was....

remove from bike, hold in hand and apply 12volts...the torq should be strong enough to almost take the motor out of your hand..if not it

needs a new motor..They do have a torq figure for it and a torq test meter but not in the UK..

Lyn.

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TheEnglishman

 

Yep - the shift motor was showing signs of wear.  A brand spanking new replacement seems to have done the trick.

 

But I've had to cancel Christmas and am eating nothing but gruel 'till Easter.

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Tex

Glad you got it sorted Neil, but sorry to hear it cost so much.. :( 

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