Topic: Restricted to 1st gear and Neutral only

[CB500FK0]

Can you put the stock shifter back in place?

Yes, I can. However, it doesn't make any difference.

[CB500FK0]

The shaft can have no effect but if the point of the "tooth" that engages the pins is damaged that would

How can I check the point of the "tooth"?  If "the point of the "tooth" is damaged, would it still reliably mesh with the first and neutral positions, but not with second gear or higher?

[scottly]

Watching the video you posted in reply #34, it looks like the bottom end of the spring is interfering with the fork thingy on the end of the shifter shaft, limiting it's travel??

[enwri]

Looks to me like it's hitting here. (red circle)   
What is the round bit and can the relief that is cut in it be rotated anti clockwise a few degrees? I've never seen inside one of those, don't know if it's possible.

[scottly]

After looking at various views, it appears the spring was an optical delusion. However, watching the video in reply #10, it looks pretty clear that the underside of the piece that hooks the pins is hitting some round plug. You can hear it hit in the video. I don't know what that part is, but I'm guessing it shouldn't be sticking out of the case like it is??
Edit: enwri beat me to it!

[CB500FK0]

It looks pretty clear that the underside of the piece that hooks the pins is hitting some round plug. You can hear it hit in the video. I don't know what that part is, but I'm guessing it shouldn't be sticking out of the case like it is??
Edit: enwri beat me to it!

OMG! scottly & enwri, you two have teenager ears and eyes that I no longer possess. That's the problem indeed. How did that piece shift out, and how can I push it back in so that it stays in place?

[scottly]

Teenage!!???  That part appears to be a transmission needle bearing, that is located in the case with a pin. I'm guessing the slot is to allow oil into the bearing? It "looks" like the slot is supposed to be at the top? Can you move it in at all, or rotate it? Don't use brute force! If it is free to move, the locating pin must have been left out, and the cases will have to be split to replace it. Hopefully someone with first hand 500 experience will chime in.

[enwri]

Teenage!!???  That part appears to be a transmission needle bearing, that is located in the case with a pin. I'm guessing the slot is to allow oil into the bearing? It "looks" like the slot is supposed to be at the top? Can you move it in at all, or rotate it? Don't use brute force! If it is free to move, the locating pin must have been left out, and the cases will have to be split to replace it. Hopefully someone with first hand 500 experience will chime in.

So no hammer or angle grinder? I'm out too..

[CB500FK0]

Can you move it in at all, or rotate it? Don't use brute force! If it is free to move, the locating pin must have been left out, and the cases will have to be split to replace it.

With my hands alone, I am unable to rotate or move it inward or outward.

[scottly]

Try tapping it back in using a wooden dowel as a punch? 

[scottly]

Just had a thought: maybe that slot is there to give clearance for the shifter part, and has rotated out of position rather than shifted outwards?

[CB500FK0]

I tapped it back in using a wooden dowel as a punch, but it moved back out once I started to rotate the rear wheel. I came across a couple of pictures online, and it's clear that mine is outward.

[CB500FK0]

That blind needle bearing is held in place by a locating pin when the main cases are put together.

@pekingduck, is that pin listed below?

[pekingduck]

No, it's on the output shaft here.

[CB500FK0]

No, it's on the output shaft here.

@pekingduck, Thank you for pointing the correct part. Is this a commonly reported issue with the early CB500Fs? So, would it be necessary to remove the entire engine from the frame to fix this issue?

[grcamna2]

No, it's on the output shaft here.

@pekingduck, Thank you for pointing the correct part. Is this a commonly reported issue with the early CB500Fs? So, would it be necessary to remove the entire engine from the frame to fix this issue?

The engine needs to be removed from the frame and then the crankcase upper and lower halves need to be separated/split so you can access that locating pin.

[bryanj]

It is definately NOT a common Honda fault BUT a common mistake of people rebuilding the 500.
There is a hardened steel locating pin in the crankcase the locates the bearing via a blind hole in the machined steel piece that is the outer race, if not located correctly on assembly the pin is pushed into the case cracking a piece out of the casting(this bit is not totaly destroying) which alows the bearing to move, this can cause excessive wear on the bearing needles and, unfortunately, the gear shaft end that is the inner race.
The only proper fix is engine out, all side covers, points plate etc off and remove lower case.
You can them extract the pin, which is in top case, and carefully refit with a bit of epoxy in the hole to seal the damaged case==not too much or the pin will stick out too far, carefully inspect the shaft and bearing for wear, luckily there are lots of used gearboxes out there you can get bits from BUT Honda did modify the tooth profile on a couple of gears through the years so if you do go used fit both shafts with all the gears OR transfer all your gears to another shaft but use new cirlips.
NOTE  CB 550 shafts and gears WILL NOT FIT.

Have you only recently got this bike? As i suspect its been apart not long ago.

The job is not difficult, hardest part is getting mounting bolts out if corroded and i have, when a lot younger and idiotic, lifted the 500 engine out and in on my own, easier if you remove sump and strainer, oil filter housing and top cover from cam cover.
If you need the proper Honda manual i can point you at a download or even send you a dvd for post cost from UK

[CB500FK0]

Have you only recently got this bike? As i suspect its been apart not long ago.

Yes, I have. The previous owner had it restored/rebuilt at motorfastca shop.

Thank you, bryanj, for taking the time to provide me with such helpful information. I would greatly appreciate it if you could share a link for me to download the proper Honda manual. 🙏

[dave500]

As said, simultaneously push up on the gear lever and rotate rear wheel and clutch spline. These are straight cut gears and may (will) clash. Seeing very little movement on the mechanism on the up stroke on the vid.

these are constant mesh gears phill,as most gear boxes are,the actuall gears dont disengage,they slide and dogs and slots within the hubs of the gears do the engagement between them,they freewheel when not used.

[dave500]

on the 550s that bearing recieved its own oil pump,driven by forward motion only not rpm,if that bearing has collapsed your lucky not to have had a full rear wheel lock up,i cant see it clear enough but i doubt the cases couldve been closed fully and squarely if the locating pin was askew?but you do get ham fisted rebuilders and enthusiasts?im no stranger to these transmissions,ive busted 3rd gear dogs off,this is the only gear pair shared between the 500s and 550s,also the 350s.

[dave500]

just out of interest heres a 550 up grade,the 500s had steel freewheel bushes in the gears,the 550s had bronze bush inserts,the 550 transmission is a worthwhile upgrade,while your at it just swap the whole motor out?

ive had more than a few of these,ive always flipped the 500s or their parts,too fragile or im too hard on them?the 550 motor and transmission was a full redesign fixing all the 500s fragilities?

[bryanj]

Go to sohc.co.uk which is the uk site like this, on the top you will find alladins cave, click on 500 and there are two different years of manual the 500=550 has all the 550 supplements to the original 500, these are designed for Honda dealers and assume you are a mechanic not a total newbie so read with care, unfortunately i have to be rude and say the people that rebuilt it have not a clue what they are doing, have you any idea what parts they fitted?

To get the bottom case off you can leave all the top end together but you need to remove the primary shaft, no special puller just remove the bearing plate on clutch side, remove oil pump complete and use a SOFT drift to tap out the shaft from the pump end watching where all the bearings and spacers go.
Take some pics with the shafts out, vids are no good to me i cant view them.
I will help all i canbut remember the time difference UK to US plus i will be away for a holiday at end of next week.
To rebuild you will need a good torque wrench and Hondabond or similar NOT SILICONE RTV.

[CycleRanger]

Have you only recently got this bike? As i suspect its been apart not long ago.

Yes, I have. The previous owner had it restored/rebuilt at motorfastca shop.

Thank you, bryanj, for taking the time to provide me with such helpful information. I would greatly appreciate it if you could share a link for me to download the proper Honda manual. 🙏

You can get all the shop manuals here: https://www.honda4fun.com/materiale/documentazione-tecnica
Don't worry, they are in english.
I wonder what kind of warranty that motorfastca place offers. Probably wouldn't carry over to you from the previous owner but it might be worth checking.
Repairing this problem isn't a simple job.

[grcamna2]

I agree with what member 'dave500' is recommending here;upgrade to a 550 bottom-end and get the much better transmission.

[RAFster122s]

Put a 550 motor in it so you can have a running bike, then do your teardown and repairs...you will be happier in the long run
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