Author Topic: Gearbox  (Read 5963 times)

Offline matthewmosse

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Re: Gearbox
« Reply #30 on: April 03, 2018, 08:38:41 PM »
Personally I would be looking for another engine, some bad damage there. Deffinately a full strip down and really good clean up to remove all the debris. Check the cases are all good including those pins behind the clutch cover that prevent bearings spinning that so often pop the top of the cover, check everything, before buying bits as that looks like it has potential to add up to a costly repair, if the top end is good a decent cb550 bottom end shouldn't break the bank - the bottom ends seem to fail less often in my experience.
Got a 500/4 with rust and a sidecar and loadsa bits. nice and original and been round the clock

Offline cb550k-aaron

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Re: Gearbox
« Reply #31 on: April 03, 2018, 08:59:31 PM »
I might looking a new bottom end tbh. Bar the gears do the selectors all look ok? I need to get parts ordered asap

Offline Trigger

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Re: Gearbox
« Reply #32 on: April 03, 2018, 09:18:59 PM »
The dogs look reasonable but, will need measuring up. Just had another look at the bearing journals and you can see that the bearings have been spinning. I would be looking at another bottom end as by the pics it all looks wrong. 

Offline cb550k-aaron

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Re: Gearbox
« Reply #33 on: April 03, 2018, 09:59:45 PM »
Does anyone have any NOS of the gears I need before I get them elsewhere? I'd rather give to another member

Offline cb550k-aaron

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Re: Gearbox
« Reply #34 on: April 04, 2018, 06:55:42 AM »
I have most of the gears NOS from the 500, list the part numbers you want and I may have them, they do share some gear just not all.

23431374000
And
23441286020

Cheers let me know


Offline Bryanj

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Re: Gearbox
« Reply #35 on: April 04, 2018, 07:23:49 AM »
That has been assembled with total lack of care in the pasty and a different bottom end is the way to go rather than attempt a salvage job

Offline Trigger

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Re: Gearbox
« Reply #36 on: April 04, 2018, 07:43:25 AM »
That has been assembled with total lack of care in the pasty and a different bottom end is the way to go rather than attempt a salvage job

With Bryan on this one. Just by the pictures, it needs a lot more than a couple of cogs  ;)

Offline cb550k-aaron

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Re: Gearbox
« Reply #37 on: April 04, 2018, 08:17:32 AM »
That has been assembled with total lack of care in the pasty and a different bottom end is the way to go rather than attempt a salvage job

With Bryan on this one. Just by the pictures, it needs a lot more than a couple of cogs  ;)

Yea I get that, but the rest of the Gears are fine so is there any point replacing all of them?

Bar the Roller Bearing housing pins can you suggest what else I should be aware of?

I really appreciate all the help.
Thanks

Online AshimotoK0

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Re: Gearbox
« Reply #38 on: April 04, 2018, 08:36:45 AM »
That has been assembled with total lack of care in the pasty and a different bottom end is the way to go rather than attempt a salvage job

With Bryan on this one. Just by the pictures, it needs a lot more than a couple of cogs  ;)

Yea I get that, but the rest of the Gears are fine so is there any point replacing all of them?

Bar the Roller Bearing housing pins can you suggest what else I should be aware of?

I really appreciate all the help.
Thanks

I get what you are saying .. I had a similar dilemna with my 750K0 gearbox (no horrific damage though just slightly worn dogs etc.) .... but in the end I got a low mileage  gearbox (transmission  ;D)   from the States  and literally everything was in near perfect condition on it ... it would have cost what I paid just to replace the bearings alone.
“Alright friends, you have seen the heavy groups, now you will see morning maniac music. Believe me, yeah. It’s a new dawn.” Grace Slick, Woodstock '69 .. In the year of the Sandcast.

Offline cb550k-aaron

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Re: Gearbox
« Reply #39 on: April 04, 2018, 08:56:44 AM »
That has been assembled with total lack of care in the pasty and a different bottom end is the way to go rather than attempt a salvage job

With Bryan on this one. Just by the pictures, it needs a lot more than a couple of cogs  ;)

Yea I get that, but the rest of the Gears are fine so is there any point replacing all of them?

Bar the Roller Bearing housing pins can you suggest what else I should be aware of?

I really appreciate all the help.
Thanks

Or when you guys say bottom end do you mean everything? Gears, casjngs, main shaft etc etc?

Offline hairygit

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Re: Gearbox
« Reply #40 on: April 04, 2018, 09:07:08 AM »
Yep, as if the bearing has spun in the casings, they are well and truly bug**ed. Basically a "Bottom end" is a complete engine minus head and barrels
If it's got tits or wheels, it's hassle, if it's got both, RUN!!!

Offline cb550k-aaron

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Re: Gearbox
« Reply #41 on: April 04, 2018, 09:09:22 AM »
Yep, as if the bearing has spun in the casings, they are well and truly bug**ed. Basically a "Bottom end" is a complete engine minus head and barrels

 :'(

Sake lol. Ok anyone got a good bottom end for sale?

Offline cb550k-aaron

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Re: Gearbox
« Reply #42 on: April 04, 2018, 03:58:11 PM »
I'm not sure if a bottom end IS the way to go TBH, there is a lot of damage sure BUT the problem is the new bottom end isn't guaranteed to be any better unless it comes with one of course. TwoWheelSpares on E-Bay have some complete engines but no bottom ends, your never sure on what the crank shells are going to be like on another engine, his may be new but they don't transfer as we know unless your really really lucky.

Really blowing the pics up shows what I suspect has happened, just above the mainshaft 3rd gear where it is missing 2 teeth there is another tooth with just the leading edge missing, I suspect this came off, jammed between the gear teeth just below it when second was engaged, this would mean this gear cluster was sitting to the left, when the 2 teeth came off they were in close proximity to countershaft second and they jammed between the 2 gears, would explain why no teeth are missing from mainshaft second, which is puzzling as you'd expect them to be meshed but again I think maybe third was in the process of being selected. The selectors look fine, which again is puzzling as you'd expect them to be the cause of this but they clearly aren't. Maybe the PO was a bit clumsy and started the process by catching the 3rd gear tooth edge. Looking again at the pics you can see new damage just under the primary chain and again to the left of that, these were no doubt the result of all the debris getting flung out of the gearbox.

I'm not convinced the bearing spun in the casings, I've never seen them do that before even when the knock pins are squashed flat to the case as in this case, I'd like to see some pics of those bearings in detail to say for sure though, if they had I'd expect to see some damage to the knock pins and I can't see that.

I'd also think about just replacing the entire box,

 https://www.ebay.co.uk/itm/Honda-CB550-CB-550-K-F-Four-1974-1978-Gearbox-Gear-Box-Assembly/332536863177?hash=item4d6cbdd9c9:g:V5oAAOSwzRFabzr4

If you just buy a bottom end your going to need a complete set of gaskets as well, plus some time stripping both engines to see if there is any damage. However I'd also point out that the damage caused by crushing the 2 knock pins can sometimes be significant, I'd like to see pics of the sprocket area from the outside to see if the pin came through the casing and also of the clutch area for the same reason.

Oddjob, I've added two pictures of the pins where they burst the casing. These were sealed and are 100% no leaks etc. I'll take pictures of the bearings etc and upload them later on.

Offline cb550k-aaron

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Re: Gearbox
« Reply #43 on: April 04, 2018, 05:49:43 PM »
Those both look to be recent breaks, has the engine been apart recently?

Around 2 Years ago for a full overhaul. Them pictures were taken at that stage not recently.

I added the bearing pictures etc to same link

Offline Trigger

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Re: Gearbox
« Reply #44 on: April 04, 2018, 05:51:53 PM »
I'm not sure if a bottom end IS the way to go TBH, there is a lot of damage sure BUT the problem is the new bottom end isn't guaranteed to be any better unless it comes with one of course. TwoWheelSpares on E-Bay have some complete engines but no bottom ends, your never sure on what the crank shells are going to be like on another engine, his may be new but they don't transfer as we know unless your really really lucky.

Really blowing the pics up shows what I suspect has happened, just above the mainshaft 3rd gear where it is missing 2 teeth there is another tooth with just the leading edge missing, I suspect this came off, jammed between the gear teeth just below it when second was engaged, this would mean this gear cluster was sitting to the left, when the 2 teeth came off they were in close proximity to countershaft second and they jammed between the 2 gears, would explain why no teeth are missing from mainshaft second, which is puzzling as you'd expect them to be meshed but again I think maybe third was in the process of being selected. The selectors look fine, which again is puzzling as you'd expect them to be the cause of this but they clearly aren't. Maybe the PO was a bit clumsy and started the process by catching the 3rd gear tooth edge. Looking again at the pics you can see new damage just under the primary chain and again to the left of that, these were no doubt the result of all the debris getting flung out of the gearbox.

I'm not convinced the bearing spun in the casings, I've never seen them do that before even when the knock pins are squashed flat to the case as in this case, I'd like to see some pics of those bearings in detail to say for sure though, if they had I'd expect to see some damage to the knock pins and I can't see that.

I'd also think about just replacing the entire box,

 https://www.ebay.co.uk/itm/Honda-CB550-CB-550-K-F-Four-1974-1978-Gearbox-Gear-Box-Assembly/332536863177?hash=item4d6cbdd9c9:g:V5oAAOSwzRFabzr4

If you just buy a bottom end your going to need a complete set of gaskets as well, plus some time stripping both engines to see if there is any damage. However I'd also point out that the damage caused by crushing the 2 knock pins can sometimes be significant, I'd like to see pics of the sprocket area from the outside to see if the pin came through the casing and also of the clutch area for the same reason.

I disagree Oddjob, the pins are lower than the journal surface and I can see the marks on the journal where the bearing has turned and then gone tight and stopped as the engine heated up and the spun when it has cooled.
Seen this tooo much lately with customers engines, as they have tried to rebuild their own motor and then bring it to me saying, it is jumping out of gear.   

 

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