Honda-SOHC
SOHC.co.uk Forums => CB500/550 => Topic started by: Erny on August 05, 2019, 09:46:31 PM
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Time to work on another iusse I'd like to fix (low prio till now).
I have shifting issues on lower RPMs, typically when cruising in city traffic or smooth ride (slow acceleration, shifing on low RPM up to 3-4k)
It is almost impossibble to shift up from 1->2, 2->3, 3->4 nomal way, practially always neutral appears (between 1 and 2) or false neutral between 2-3 and 3-4.
4->5 usually works
Scenario:
When I shift, I move lever all way up and feel I cannot move more, like there is some block, more force does not help, so only neutral is engaged. If I try to keep it lifted up longer I feel block is released and upper gear is engaged, but not always. Most of the time I have to release cluch and lever, then press again clutch and then i can shift from neutral to upper gear.
You can imagine it is very annoying when starting from traffic lights, you want to be fast, but then 1-neutral-2...shame ::)
What is strange, shifting 2->3, 3->4 works fine in higher RPMs (stronger acceleration), or at least I don't observe it. Shifting 1-2 in higher RPMs is not perfect too (neutral appears) but better than in lower RPMs.
Donwnshifting is OK, all gears, all RPMs.
Clutch works perfectly, very smooth.
I suppose this is not just a standard "feature" of 550.
Was thinking if it can be related to oil used?
I use mineral MOTUL 4T 3000, 20W 50, the same as on my CB750 K7 (that works perfect)
Any other ideas?
Should I be worried that I need to open engine? It was not open yet, 15.000 miles on the clock.
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Try just partially pulling in the clutch.
Sounds like the gears are not turning at relative speeds. So they don't mesh and engage.
In many ways. It is more difficult to ride slowly than fast
Sent from my SM-A750FN using Tapatalk
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You are (trying to) ride it like a Harley.
You can imagine it is very annoying when starting from traffic lights, you want to be fast, but then 1-neutral-2...shame ::)
If you want to be fast, why are you shifting before 3-4 k rpm? How fast are you going in first gear with those revs? 15 mph?
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You are (trying to) ride it like a Harley.
You can imagine it is very annoying when starting from traffic lights, you want to be fast, but then 1-neutral-2...shame ::)
If you want to be fast, why are you shifting before 3-4 k rpm? How fast are you going in first gear with those revs? 15 mph?
does not make sense to deeply discuss it, it is depedning on situation, style, mood...simply why not? Shifting in low RPMs was never a problem for any other bike I had or I have, except this one.
So that's why I'm asking if it is normal or not.
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Totally random thought here....have you had gear change lever off recently and if so, did you reposition it correctly on the spline with the dot on the spline and the dot on the lever lined up? I also find my gear change is very tight in all gears at low revs when the engine is hot....this is a normal thing with these old Hondas and many forum members experience this.
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I can't see the oil making much difference to it.
Most bike gearboxes are constant mesh, meaning the paired gears are running together all of the time so you don't ordinarily engage the teeth to change gear.
The gearbox dogs are how each ratio is connected in sequence to direct drive through each pair required. These aren't usually obstructive as they have significant spaces to move them in and out of position.
The problem you describe "sounds" like you've possibly got one or more of the selector forks bent. What this does is not push the gear being moved all the way into its correct engagement, making it easy for the forces applied to push it back out from where you are trying to place it with the lever. That's how false neutrals can occur.
IF that is the case, it can't ordinarily be seen without dismantling to check the selector forks as far as I'm aware.
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[attachimg=1]
It's these forks that can be susceptible to bending that we discussed on another thread. These were for sale which I believe a forum member bought to replace some damaged in their own engine.
The 750 gearboxes appears to be less affected on their own versions of these forks, so although a bit clunky sometimes they are generally tough and operate correctly.
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It is worth removing clutch cover and clutch to inspect the gearchange mechanism.
All of that has to come off to split the cases so it is not wasted work.
The problem you have i have never heard of on the 550 so you are flying blind and looking for something unusual.
Remember Mcgintys third law:-
In a piece of machinery, no matter how reliable, at least one of everything will wear out sometime somewhere.
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Not sure what gearbox bits a 550k1 has compared to cb500 or cb550k3 which is what I have experienced but on either when running and setup right they have been really nice and slick through the gearbox - my cb500/4 was regularly able to go from my place up in the hills of Mid Wales all the way to my girlfriends ( now wife ) old place in Talbot green by Cardiff, that's over 90 miles mixed A, B roads plus dual carriageway and back onto B roads and in the entire trip I would only need to use the clutch 3 times, the rest of the time I could just shift through the gearbox smoothly with not even the clutch being touched or any clunks. That is the measure of a good cb 500 gearbox, not sure my cb550 was quite as silky smooth, but close.
I had a few cb500 and 550 gearboxes act like you describe or more stubborn - yet at standstill they go though the box perfectly. I'm afraid I never bothered to resolve the issue, I had other engines so these stubborn ones are still in the loft. At least 1 was newly rebuilt by me from good used bits and all looked in good shape - I suspect it was something like the clutch pushrod on that one, as it was a 3 part affair with a ball bearing - I now believe that's not exactly as Honda intended. Back then I was using a cb550 manual as a guide and did not have this excellent forum to trawl through or ask for help.
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All the 550's are theme except for upgrades during manufacturing life but are completely different from 500
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Searching back through my memory I did have similar gearshift issues off a cb550, was something undef the clutch cover, cannot remember what. Mostly I remember tipping then bike over so as to not loose the oil while fixing it.
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I was afraid of this feedback... Opening engine was something I wanted to avoid
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I was afraid of this feedback... Opening engine was something I wanted to avoid
With only 15,000 miles Erny, I would consider and investigate all other options before taking the engine apart.
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Sure! Opening engine is the LAST action.
It is pity that gearbox cannot be replaced w/o opening cases like on nowadays bikes
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Start on clutch casing and release mechanism, I have a hunch that was where my problem lay. How good is the clutch cable? Start with the easy stuff.
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Clutch cable is new (OEM), operates perfect as far I can say (compare to any other Honda I know).
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I just realised that I never introduced myself here on the forum (joined 1 year ago) - I appologize for that ::). I think now it is too late
So at least here are 2 pics showing my 550. Someone maybe recognize her, it comes from one well known forum member here ;)
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She’s a beauty Erny. Definitely in the right hands now. Great photos.
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Thanks James! And also for all support provided! ;)
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Great looking bike ;D
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That is a sweet looking bike.
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Coming back to this topic - is there reliable way how to ensure issue comes from bent/work shifting fork or other issue that will force me to split cases?
I want to go maximum avoiding that.
Just thinking, maybe inspection camera?
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Unfortunately not, the tips of the selectors is where you will see wear and they are hidden in the grooves of the gears so not visible till removed, if poor selection is only one way i would suspect mechanism more than selectors.
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Thinking further about this, it's worth splitting down what happens inside to give a better picture of the problem.
I can quite understand not wanting to split a factory built motor, it's nice to have something very original.
To make a statement of the problem :- the second gear engagement dogs are either not fully in position when applying torque through the gearbox or the dogs themselves are worn rounded at their edges, both of which can force the gear back out of engagement and give that false neutral.
Discount the worn dogs for now, just set aside as they shouldn't at that mileage be compromised.
Positioning is achieved by completing the selector drum rotation until it locates the drum in its detent. At that point the gear should be fully engaged. If you don't fully rotate the selector drum the gear is left partly in full engagement, resulting in the gear being forced back out when you apply throttle.
This would be either something wrong with the mechanism that rotates the drum, or the detent that should hold it where you left it after moving the lever.
The operation of this can be inspected after removing the clutch on this engine, without removing or splitting the engine. But you need to make sure that your foot is moving the lever fully when changing up to second to ensure you are not missing something simple here before going inside to inspect.
If the selector drum completes it's rotation and is held by detent but the gear still spits out under load, then it would point to more internal parts that would need a split.
A road test like this will help seperate the two areas :- get out and up to third gear, then change down into second, now leaving it in second gear use full throttle to accelerate, don't change any gears now, shut the throttle and let speed come down again, now repeat. You need to be quite violent in doing this in second gear and then go further by opening and shutting the throttle in quick succession.
What you are testing for is the correct position of second gear location under more extreme loading. It shoukd not pop out of gear if you subject it to this as you are testing both the forward and reverse torque capacity of that gear set. It should just stay in that gear without question.
If this checks out ok, it shows the ability of that gear to operate correctly, confirming that the gear is placed fully and it's dogs are in good condition.
It's quite possible for low mileage gearboxes that have been used very gently to be obstructive, which is probably move related to the machining quality on the shift drum. If that's the case, then very close attention to placing the gearlever as close to your foot as possible will definitely help you. The change from 1st through neutral to 2nd is the longest travel required on these bikes. If you don't make full and positive travel right at the end of the movement it can leave the selector drum short of its detent position.
The clutch on bikes makes almost no difference to gearchange operation, unlike a car they can be helped by not pulling the clutch all the way in, as John mentioned earlier.
All of them should change without clutch at all if the throttle is well set up to allow rider to accurately control torque.
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Thanks for the feedback
I did road test many times already when riding in my favorite track (uphill, many curves) - so full trottle, shut, full again on 2nd gear many times (believe me I was violent enough) no single issue, 2nd stayed engaged all the time. And as I said before, shifting on higher rpms is all ok.
Concerning lever travel - fact is that I dont have dot on shaft to know exalt position of lever (on lever dot is clearly visible), so I set to my best guess. Not sure if eventual shift by 1 tooth can cause this.
It simply behaves the way when i shift up that I feel something blocking lever to go up more. Either I keep it lifted all possible way up longer and it enegages (lever moves more up) or release it and do second lift to engage it correctly.
I'll open clutch anyway to check it.
Practical question here - is it enough to lay bike on left side to avoid draining oil?
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If the lever is out by one or more notch upwards on the spline, the lever can easily foul on the casing when changing up through the gears. Because there is not enough room for complete upward travel of the lever, it may not be engaging the gears correctly at first lift of the lever. As a simple experiment, remove lever from shaft, position lever nearer the ground on the spline and see if it makes any difference. It will may not feel a comfortable position for your foot but, temporarily, it is worth a try. Not sure why you haven't got dot on end of shift though, most strange.
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Try changing gear without using the clutch. Just briefly ease the throttle as you move the lever.
Try to move it all way. As far as the lever will go.
Ideally wear a pair of light shoes so you can feel the engagement.
Sent from my SM-A750FN using Tapatalk
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Practical question here - is it enough to lay bike on left side to avoid draining oil?
Yes ok if you need to look in there. Make sure your battery is spill proof or remove it before doing this to prevent acid leaking.
You can use an old car tire with a clean sheet or similar to lay it on, remove side panel etc to avoid damage.
I set my gear lever currently for bike boots with a patch on them, but if I go out with just trainers I can get false neutral there from them not reaching as high. It's only a small difference but it shows with a false neutral if I don't concentrate.
It is a slightly cumbersome action of rotary motion (selector drum) converted to linear action (movement of selector fork) a bit like a very big nut and bolt as they move. It's a wonder they work as smoothly as they do generally.
If its staying gear under full loading it does suggest that the selectors, dogs etc are all OK and avoid any need to split the engine.
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If the lever is out by one or more notch upwards on the spline, the lever can easily foul on the casing when changing up through the gears. Because there is not enough room for complete upward travel of the lever, it may not be engaging the gears correctly at first lift of the lever. As a simple experiment, remove lever from shaft, position lever nearer the ground on the spline and see if it makes any difference. It will may not feel a comfortable position for your foot but, temporarily, it is worth a try. Not sure why you haven't got dot on end of shift though, most strange.
Julie not sure if I understand you - I do not see how lever can foul on the casing...
Found pic before I disassembled lever (but not sure if it was correct as there is missing dot on shaft and not sure if shifting was working fine as I did not tested it enough ) and after - how it is now. You can see I put it lower then it was.
To me it is just shaft with notches that allows in principe lever to be adjusted according rider's preference so shall not normally create such issue.
Maybe if someone has pic showing proper lever position on the shaft - I can test it.
(https://uploads.tapatalk-cdn.com/20190819/2f1fd8df12cbdbfa7b57f48c9b61fd4d.jpg)(https://uploads.tapatalk-cdn.com/20190819/e03457aeb2e177825e8db4c913a5f066.jpg)
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Haha, yes Erny, you will not understand me because I am remembering another bike where the lever touched the casing 🙄🙄🙄 Are you sure there is not a dot there, it may be so small an not even look like a dot but it must be there somewhere. I cannot increase size if your photos to see properly though.
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Your current picture shows the gear lever one or two splines further up than the original position, that will definitely make a difference.
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Just to be sure, this is how it is now, so you think I should move it even lower? (https://uploads.tapatalk-cdn.com/20190819/9f19415c933cac02400f0f8151cf0034.jpg)
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I thought the pictures where the other way round.
As long as you set it so that it's as close to your foot as possible but without it being constantly moved, then that's the best you can get it.
It should be able to rest so that you don't drive it with any constant pressure on the lever, but you need the most travel you can get with your foot to complete the gearchange action.
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After loooong time (yes, more than 3 years!) I'd like to update this thread.
Up-shifting issues is still there, getting a bit worse now.
Meanwhile I was testing and testing.. my findings:
- only pb is in up-shifting (down-shifting seems to be normal to me, w/o any fail)
- issue is present ONLY when using clutch
- while up-shifting w/o clutch (short trottle release and quick lever moving up), it works perfect, smooth, even in lower RPMs
- when starting up from zero (for example when standing on traffic lights), while fluently releasing clutch as normal, bike starts to pull, but when clutch becomes fully engaged bike "kicks" (not sure how to describe it better, as English is not my native language...). This was present since I got the bike but I attributed it to hardened rubbers in rear wheel sproket carrier. Now having those rubbers new, I know it is something in engine/clutch.
Considering all above, I suspect it is clutch responsible for those issues, so I need to check it (winter project)
I tried to search quickly forum, did not find similar problem described - do you have some idea what is wrong?
Or, at least, recommend what I should be prepared prior opening engine (clutch cover)? I already have new gasket ready...
Thanks
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I would suggest checking the gear change mechanism behind the clutch basket, there are 2 hooks which catch the pins in the end of the gear selector drum, one pulls the pins and one pushes them. I suspect the pull one could be rounded off or be bent out of alignment. Also check the pins for any signs of damage just in case.
The kick we would probably describe as clutch snatch, this could be anything from a distorted clutch disc, a worm drive fault in the sprocket cover or even a broken clutch push rod, you’ll need to check everything as you take it apart. I’d also suggest checking the clutch basket to see if the large drive gear on the back has started to come loose or even if the internal damper rubbers are perished, see if you can find any movement in the gear whilst holding the basket firmly.
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Thanks, Ken, will check that
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After some time, I finally opened cluch cover (was first one opening it, BTW). Note: engine now has 19k miles from new
Winter was simply too cold to to motivate me doing it in cold garage, moreover I was lazy :D
Back to point - I tried to make few videos from my findings, please comment advice what is/can be wrong with regards to my up-shifting problem and clutch snatch/kick:
1. Clutch basket has serious axial play, I measured approx 0.7mm https://youtube.com/shorts/_LvZtXY1b3Y?feature=share and https://youtube.com/watch?v=o-TgZ4Vp3Ms&feature=share
2. Hooks on gear change mechanism seems to me Ok, see photos
3. Gear mechanism (wheel on shift drum stop?) has significant play but only in one direction, see https://youtube.com/shorts/Y626xFgk51w?feature=share - is that OK/normal?
4. Large drive gear is moving vs clutch basket, seems internal dumer rubbers are shot (can this cause clutch snatch/kick?) https://youtube.com/shorts/W4neSdbf_I4?feature=share
Other findings:
- clutch plates looks as new (friction ones has 2.68mm), no mechanical wear visible
- clutch collar and clutch basket bushing looks OK to me, but basket has some play (~0.3mm at the edge when trying to move left-right, up-down)
As I have shims from Ken, I can to fix axial play of basket.
Shall I replace damper rubbers too? If so, where to get them? What about shift drum stop wheel?
Any other ideas what I can check/do else?
My priority is to fix up-shifting issue..
Thanks
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The damping rubbers inside the basket look to be shot to me Erny. How do the towers look, where the tangs of the clutch plate sit are they still flat or are they showing ridges all up and down the towers.
Not sure on the gear selector wheel question, I'll need to compare with some of mine to see if mine do the same, never really looked at that before TBH.
I'd suggest looking for a replacement basket, new if possible. Or one that's got no play if not. Ask the seller to check.
Do the axial play when the new basket arrives.
I may have a 550 basket (not 500, they look the same but aren't) but it's the distance that kills it.
Hooks look ok. Have you checked the pins they engage with, might be a broken one.
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The clutch has non serviceable Cush rubbers. Now I never new that!
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The damping rubbers inside the basket look to be shot to me Erny. How do the towers look, where the tangs of the clutch plate sit are they still flat or are they showing ridges all up and down the towers.
Not sure on the gear selector wheel question, I'll need to compare with some of mine to see if mine do the same, never really looked at that before TBH.
I'd suggest looking for a replacement basket, new if possible. Or one that's got no play if not. Ask the seller to check.
Do the axial play when the new basket arrives.
I may have a 550 basket (not 500, they look the same but aren't) but it's the distance that kills it.
Hooks look ok. Have you checked the pins they engage with, might be a broken one.
As for the basket - It is 550 one, I'll do detailed inspection today again, except dampers play, to me clutch really looks OK.
As for dampers - my fried was replacing these dampers on his 650 SOHC engine (shall have similar ones, I guess), he drilled rivets out, one guy made rubbers (from some plastic material) for him and then he used bolts to close it. And it is working well (racing engine).
Main question is if such axial play (0.7mm) could cause my up-shifting issues? Or that gear selector wheel ...
Need to inspect pins too that bolt hooks are engaging but I do not expect issue as up-shifting issue is on all gears and shifting works smooth w/o using clutch, will report anyway.
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With regards to basket axial play - just found that it is linked to collar length vs basket length - it is quite big to me (but maybe normal?). Only way to reduce it is to put shim under collar shoulder (between collar and basket), but Honda manual does not say a word about it, just mentions shims behind snap ring..
Any thoughts?
Video - I'm holding collar pushed firmly against engine - this is axial free play of basket (~0.7mm)
https://youtube.com/shorts/kOtujX2WB-I?feature=share
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Just to give you the update on this
Since last post I ordered few parts:
- shift drum stopper, neutral stopper and stopper cam plate replaced by new ones
- new clutch springs
- basket filed
- basket play adjusted (thanks to Oddjob's shim set!)
- assembled, new oil, filter etc
I did not do anything with dampers in clutch basket - I'll keep that for later (winter job, highly likely engine to be opened anyway for primary chain replacement at least)
First ride : up-shifting issue is still there, but I feel it less happening / reduced.
When testing shifting mechanism before assembly clutch and cover (with new replaced parts) I did this video to show the issue that I feel during shifting - when up-shifting, I usually cannot change gear unless I turn gearbox. Down-shift is always w/o issue. It is clearly visible in the video that when up-shifting, movement of gear drum is "stuck" in the midway and moves more when I turn gear (clutch basket shaft). This is exactly what I'm referring as my up-shifting issue.
https://youtube.com/shorts/G-AaCvEzcqE?feature=share
Question is if this is normal (so no more issue) or problem is in the gearbox itself? Maybe experts here (Bryan, Graham, Oddjob..) can comment?
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To engage gears with bike at stanstil and engine not running you need to rotate at least one shaft, maybe both, so the fact it baulks on changing on the bench is a "normal" occurance
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Thanks Bryan for this confirmation. Hope story is over now ;)