Broken Gearbox Help!?!

[red]

My trusty CBR has suffered misfortune last week.

Taking it to work and out of the village, I couldn't shift up past three. I can just about shift between 1-N-2 but it's more clunky than you'd expect it to be.

I've just rung my local bike place and they've basically said they'd not look at it if it involved opening the engine which it's ultimately going to end up needing from what I can tell.

Their reasoning behind this is that you'd be looking at £150 in gaskets before you'd even looked at the parts to repair the problem and the labour to do so. They're recommending considering a replacement which would be around £1k all in he reckon'd and that's be less than he'd expect for a repair.

Now I don't know enough (read any) about bike gearboxes and how they sit inside the engine but I suppose given their compact size it's all quite integrated.

There's engines on eBay going for around the £350 mark but with only a month warranty and mileage all reasonably high, how do you know you won't just fit another lemon waiting for the same fate?!?!

:-(

 

[oilburner]

It sounds to me more like damaged selector forks or selector drum barrel than a damaged gearbox, can you shift through the gears with the engine not running?

 

[stuvy]

I too would look at fork selectors. What's your bikes mileage? Iv never had a box go even when I raced

 

[red]

I will try when I get in, do I expect to be able to shift through with it off it that's the case?

 

[tuonokid]

Selectors for me as well but worth trying adjusting the clutch up and checking the oil level in the engine.
Barry
PS It might be and idea to take off the rearset linkage and make sure that's ok as well.

 

[Frank]

[post]360050[/post] Their reasoning behind this is that you'd be looking at £150 in gaskets before you'd even looked at the parts to repair the problem and the labour to do so. They're recommending considering a replacement which would be around £1k all in he reckon'd and that's be less than he'd expect for a repair.

Well, there's a surprise.

Do you reckon these garage guys are all related to each other? I'm sure that, in the past, I've met that guy's son, father, uncle and grandad.

I also reckon there's a school somewhere where they all take classes in 'Pained Facial Expressions' and 'Sharp Intakes of Breath'.

 

[oilburner]

It's a massive amount of labour to replace most motorcycle gearboxes as it involves removing the engine then splitting the crankcase, that's why most race bikes have what's known as a cassette type gearbox. If you can select the gears ok without the engine running then it points to a gearbox issues. How does the chain feel too?

 

[Frank]

[post]360061[/post]
It's a massive amount of labour to replace most motorcycle gearboxes

True, but doesn't it strike you as odd that they don't appear to have taken any diagnostic steps or assessed other possible causes before coming up with that recommendation?

 

[red]

I thought that too Frank, I've been using this place years too..it's the most 'biker' garage around. I daren't even call the dealership. "Hi I have a 15 year old Honda..." that's probably as far as it'd get before they tried pitching a new bike.

Anyway..back to the previous points, I tried moving it with the engine not running and it's the same. 1N2 but even selecting through these doesn't feel right.

 

[tuonokid]

Hi Red
Have you tried all the other non invasive points mentioned above and is there a rearset linkage on it that may be seized or partially seized?
Barry

 

[red]

Other than trying to shift with it not running the only thing I've done is have a visual inspection of the linkage which doesn't look like there's anything wrong with it. It can't be chain related since it doesn't work not running.

The splines look fine too.##I will have another look tomorrow but I'm pretty confident of the above.

 

[tuonokid]

Hi Red
Just to be sure take the gearbox shaft end of the linkage off so you can move the linkage and the lever in all directions to check for play or seizure.
Barry

 

[red]

Took the rearset off so the linkage was free, still the same though, no way it's moving up past second.

If it helps the story and it probably does, about a day or so before, I remembered thinking it felt a bit strange shifting downward i.e. when coming up to roundabouts. I didn't think too much of it at the time because it was like -2 and there could have been a number of contributing factors but it seems relevant now..

Sounds like it's seized.

 

[oilburner]

It's likely a piece of the selector fork has broken off and jammed the gearbox I reckon.

 

[tuonokid]

Hi Red
If you've checked all of the above including adjusting the clutch so that all of the non invasive methods are exhausted the next step may be to take off the clutch casing as sometimes you can see some of the gear selection stuff from in there. If you're confident enough to do that all you'll need is to drain the oil and buy a new gasket. Once you've got the casing off get someone to try and change gear whilst you are watching what's happening in the casing. Hopefully you can see something that looks amiss such as a broken spring or a bent lever (you can't always change gear on a bike when it's stood still sometimes you need to move the bike in gear so the next gear will slot in). If that doesn't work it may be something on the actual selector forks within the crankcases which is where it starts to get expensive.
I hope that helps.
Barry

 

[red]

Thank you all for the comments and suggestions, given the options:

1. Start taking it apart in my garage with limited space with limited time.
2. Replacement engine which can't be seen running with 1 month warranty.
3. Give it to a garage to investigate the current engine / gearbox, which could be like handing over a blank cheque with no guarantee of repair.

I think I'm sadly going to opt for the fourth option. Sell it 'as is'.

I'm not particularly fond of that idea but I've had it coming up 6 years and done over 20k on it so it might just be time to move on.

 

[Frank]

[post]360099[/post]
I think I'm sadly going to opt for the fourth option. Sell it 'as is'.

Pity, but I think you've analysed the position well. Sometimes there is no 'best' option, just the least worst option.

All I would suggest is to ask around first, owners clubs, etc. It's still winter, time hangs heavy and someone might fancy keeping their hand in for the cost of a big drink, plus parts. Until you ask you never know.

 

[stuvy]

Split it for parts

 

[red]

Well that is a backup option but that's a space / time thing too.

 

[red]

So.. I haven't put it up for sale yet but... this happened.