CBR600 F4 gearbox problem? Help!

**Rehab** · 6th January 2012, 18:41

Hi helpful folks,

Was just prepping my bike for the Cannonball Run tomorrow and had finished cleaning the chain with it up on the centre stand. Popped it into gear to help fling off the cleaner before lubing it and something has gone HORRIBLY wrong. There is a noise in the gearbox similar to a stone flying around in there and it's catching so badly it nearly rocked the bike right off the stand. Obviously I won't be finished diagnosing and repairing the problem in time to do the Cannonball tomorrow so I have to pull out. Absolutely gutted.
Anyway, I was hoping someone could give me some helpful advice on the best way to diagnose the fault before I start pulling things to bits. I s'pose I could just trailer it to C'treads in the morning but I'm on a zero budget here so would at least like to know what the problem is before I start spending money. The wheel turns just fine by hand in neutral, so it aint a chain or rear wheel problem. Guess it's a pretty sure bet it's the gearbox, but can anyone suggest why this might have happened and what the likely issue is (about 85km on the bike)?
Only silver lining is I was riding earlier today and didn't notice anything at all, so I guess it could have suddenly jammed and spat me over the bars - at least I'm in one piece to try fixing the fucking thing. I have a workshop manual, the required skills if I work slowly and carefully, and I actually have a connection who has a 5000km gearbox if I need it.
Any brilliant advice??
Cheers and sorry if this is all stupid questions - bit braindead due to the massive disappointment.

PS If anyone wants a free entry into the Cannonball tomorrow let me know. You could use my pass and I haven't even put the numbers/stickers on the bike yet (luckily). Pick up from G'feild - cost ya some beer or sumfin - or just really good advice.

**tigertim20** · 6th January 2012, 18:45

bit hard to tell without hearing it. a selector lost a prong off a fork, or a tooth lost off a cog maybe.
if you have the manual, do it yourself. take it apart slowly, take photos as you go to help you with reassembly.

**Rehab** · 6th January 2012, 19:17

Originally Posted by tigertim20

bit hard to tell without hearing it. a selector lost a prong off a fork, or a tooth lost off a cog maybe.
if you have the manual, do it yourself. take it apart slowly, take photos as you go to help you with reassembly.

Thanks for the speedy reply. Busy reading the manual now. Love the photo idea - wouldn't have thought of that so already worth asking on here! Thanks heaps

**Katman** · 6th January 2012, 19:34

Bikes sometimes make weird shit noises when you idle them in gear on the centre stand all due to engine pulses plus transmission backlash plus chain freeplay.

If it rides ok there's more than likely nothing to worry about.

**tigertim20** · 6th January 2012, 19:46

Originally Posted by Katman

Bikes sometimes make weird shit noises when you idle them in gear on the centre stand all due to engine pulses plus transmission backlash plus chain freeplay.

If it rides ok there's more than likely nothing to worry about.

true, but if something has broken off inside, going for a ride on it would be about the worst advice ever . . .
the difficulty of diagnosing over the internet!!.

**Katman** · 6th January 2012, 19:47

Originally Posted by tigertim20

true, but if something has broken off inside, going for a ride on it would be about the worst advice ever . . .
the difficulty of diagnosing over the internet!!.

You appear to have just enough knowledge to be a danger to yourself........and yet, more than enough to make yourself sound stupid.

**hayd3n** · 6th January 2012, 19:55

its a honda itl be sweet

**Rehab** · 6th January 2012, 20:29

Originally Posted by Katman

Bikes sometimes make weird shit noises when you idle them in gear on the centre stand all due to engine pulses plus transmission backlash plus chain freeplay.

If it rides ok there's more than likely nothing to worry about.

That'd be awesome news. However, does weird shit noises include something catching when in gear so much that it's goes rapidly tight then slack in the chain and rocking back and forth on the stand? Serious question in case it sounds like sarcasm. I really hope it's nothing to worry about and will wait for your reply before continuing (only have the fairing off at this stage).

Edit - Think I may have answered my own question - that's way too much noise to even try and ride and see if it's ok. It sounds really bad. If I were more pooter savvy I'd record it and put it on here, but I think that'd take longer than fixing it.

**hayd3n** · 6th January 2012, 20:37

Originally Posted by Methane_Birds

That'd be awesome news. However, does weird shit noises include something catching when in gear so much that it's goes rapidly tight then slack in the chain and rocking back and forth on the stand? Serious question in case it sounds like sarcasm. I really hope it's nothing to worry about and will wait for your reply before continuing (only have the fairing off at this stage).

Edit - Think I may have answered my own question - that's way too much noise to even try and ride and see if it's ok. It sounds really bad. If I were more pooter savvy I'd record it and put it on here, but I think that'd take longer than fixing it.

take a video and upload to youtube or facebook etc etc ,
maybe drain the oil and inspect it for foreign things

**Rehab** · 6th January 2012, 20:41

Originally Posted by hayd3n

take a video and upload to youtube or facebook etc etc ,
maybe drain the oil and inspect it for foreign things

Interesting. If you point a video at it and press record it reduces the noise significantly. I'm going for a quick ride....

**Katman** · 6th January 2012, 20:43

Originally Posted by Methane_Birds

Edit - Think I may have answered my own question - that's way too much noise to even try and ride and see if it's ok. It sounds really bad. If I were more pooter savvy I'd record it and put it on here, but I think that'd take longer than fixing it.

So it ran fine, then you put it on it's centre stand and it made some noises, and now you're too scared to ride it?

**Madness** · 6th January 2012, 20:44

Originally Posted by hayd3n

maybe drain the oil and inspect it for foreign things

+1. If I had a budget of $0.00 in your circumstances that'd be the first thing I'd do.

**Madness** · 6th January 2012, 20:45

Originally Posted by Methane_Birds

Interesting. If you point a video at it and press record it reduces the noise significantly. I'm going for a quick ride....

What are you smoking?

**bogan** · 6th January 2012, 20:47

Noises are a really hard thing to convey over the internet!

I would suggest upping the idle significantly, say to 2,500, and seeing how that affects it, if it is driveline play I'd expect a fair bit of the snatchyness to go away, and just a touch of rear brake and it should all go away. If it gets worse in either case, maybe you got problems... GL