Author Topic: Canít change down gears  (Read 546 times)

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Offline Thiss

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Canít change down gears
on: 22 June, 2021, 05:40:48 PM
2009 model.

My son Ďborrowedí my bike about three years ago when he started commuting and Iíve not sat on it since.

Turns out itís now broken so all of a sudden it seems itís mine again - kids eh !

Apparently it will change up through the gears ok but not down usually. Lever moves but no one at home. He can get back to neutral if itís on the stand with the back wheel spinning but presumably no weight on it.  Iíll pop over at the weekend to kick the tyres and moan how unkept it looks but have no idea whatís the matter.    A mate says Hondas are known for gear selector issues.  A dealer said it was an engine out job and heíd be better off looking for a replacement !

Limited info at moment, but anyone had similar issues ?

Tks
Dave

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Offline jm2

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Re: Canít change down gears
Reply #1 on: 22 June, 2021, 10:22:14 PM
Could be many things but start with the simplest.

Take off all the level mechanism completely and grease the knuckle joints (2) and clean and regrease the lever pivot then you'll know that is good and not causing 'lack of maintenance' issues.

It'll also be worth checking the drive chain is free, lubed and correctly adjusted (enough free play).

Go from there, do those and reply back.
Only do it right - no bodging please.   Keeper of the failed stator list.   John.

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Offline Art

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Re: Canít change down gears
Reply #2 on: 23 June, 2021, 07:26:49 AM
*Originally Posted by Thiss [+]

A dealer said it was an engine out job
Dealer advice should be your last resource

*Originally Posted by Honda Workshop Manual

SECTION 12. TRANSMISSION/GEARSHIFT LINKAGE

This section covers the transmission and gearshift linkage service. These service can be done engine installed in the frame.

Maybe have a copy of Section 12 of the Workshop Manual to hand.

As above start with easy and remove the gear lever to gear shift spindle linkage to lubricate first, there are two pivot points and 4 ball joints to lubricate. Take care when refitting the pivot bolts, the Honda torque specification is 27 Nm which in my experience can strip out the aluminum threads, it's an easy enough fix to helicoil but an extra job you could probably do without. My preference is to thoroughly clean the pivot bolt threads, apply medium strength Loctite 243 threadlocker and just nip them up to maybe 15 or 20 Nm and then leave for 24 hours before riding for the Loctite to fully cure.

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Offline Thiss

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Re: Canít change down gears
Reply #3 on: 23 June, 2021, 09:41:53 PM
Ok, Adam has checked the external linkage and cleaned it all up - says it makes no difference.  Guessing next step is to take the side cover off and pull out the selector mechanism?

Tks for replies

Dave

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Offline Rick

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Re: Canít change down gears
Reply #4 on: 23 June, 2021, 10:05:40 PM
After your initial checks with the linkage I would be checking that the hydraulic clutch system next. Has the fluid been changed within the last few years ? it seems to deteriorate quicker than the brake fluid due to the engine heating the slave cylinder. 

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Offline Thiss

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Re: Canít change down gears
Reply #5 on: 24 June, 2021, 08:01:12 AM
He claims the clutch is working fine  :084:

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Offline Art

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Re: Canít change down gears
Reply #6 on: 24 June, 2021, 12:24:17 PM
What I'm understanding here is that with the mo'cycle supporting it's own weight changing down through the gears is only possible by placing the motorcycle on the centre stand with the rear wheel spinning.

From time to time we've all experienced a similar issue when changing down through two or more gears while stationary, where it is not always possible to change down directly from one gear to a lower gear without partially releasing and re-engaging the clutch or, by stalling the engine and rocking the moícycle forward and backward while changing gear to find neutral. By far the most common cause of this issue is the condition of the engine oil temperature/viscosity, especially if being ridden in city traffic. Of course other causes of this type of issue could also be due to a clutch fault or worn gearbox internal components such as selector forks, selector shaft and selector drum cams etc.

Letís start with simple. Clues can be taken from the mo'cycles service history, bearing in mind weíre dealing with a 12 year old moícycle that is being used as a daily commuter that may or may not have been serviced for the past three years or more. Depending on service history Iíd tend to any neglected areas of maintenance paying particular attention to a six point gear linkage lubrication, drive chain inspection/maintenance, engine oil & filter replacement, clutch system inspection & fluid replacement before exploring the possibilities of worn gearbox internal components.

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Offline jm2

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Re: Canít change down gears
Reply #7 on: 24 June, 2021, 02:21:36 PM
*Originally Posted by Thiss [+]
Ok, Adam has checked the external linkage and cleaned it all up - says it makes no difference.  Guessing next step is to take the side cover off and pull out the selector mechanism?

Tks for replies

Dave
Can we be clear on something (third-hand fixing is always troublesome)
Has he (or can you) take off all the (external) gear shift mechanism, clean, lubricate and refitted it ?

The gearbox selector mech could be completely toasted but these are the simple things to eliminate first.
Only do it right - no bodging please.   Keeper of the failed stator list.   John.

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Offline Thiss

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Re: Canít change down gears
Reply #8 on: 24 June, 2021, 03:32:22 PM
*Originally Posted by jm2 [+]
Can we be clear on something (third-hand fixing is always troublesome)
Has he (or can you) take off all the (external) gear shift mechanism, clean, lubricate and refitted it ?

The gearbox selector mech could be completely toasted but these are the simple things to eliminate first.

He says he has but Iím guessing thatís not a five minute job so I will go over this weekend and take a look myself - he can be a bit ham fisted.    Oil was changed last year apparentlyÖÖ

Tks guys