Gearbox - help!

[gabriel_gs]

The gearbox (I'm assuming!) just started rattling yesterday.

a) Is it buggered?

b) Is it expensive?

c) most important, will I be doing damage if I ride it?

Any help gratefully received!

 

[D6]

could be the clutch?

 

[pablo666]

Kinda impossible to reply too since you are not even sure that it is the GB that is rattling!

Get a long screwdriver put the handle agin yr ear. put the blade at various places around the engine to see where the noise is from.

Does the rattle get worse or better etc when the clutch is in or out? Does it get worse in or out of gear, in any specific gear, at speed etc etc................

 

[gabriel_gs]

Thanks guys...

Definitely the gearbox (with my limited knowledge!) and happens at various revs and whilst in gears.

My Dad (with slightly less limited knowledge than me, though non-the-less limited) said he thought it sounded like a 'dodgy clutch'.

Obviously I'll get it to a garage, but most importantly I'm concerned that I could be doing damage by riding it... which I need to do for the next few days!

Again, folks, any advice would be brilliant!

 

[pablo666]

'Normally' a gear box will be noisey for a long time before it fails. Obviously the longer you use it, the more damage etc and cost. For example, if a input/output bearing was wearing out it would gradually start to damage the case. If caught in time, all it would need would be a new bearing. If left, you may have to replace the case! As a general principle, the earlier you take action, the less likely that there will be any consequential damage and cost. On the other hand, ppl report travelling for thousands of miles on a dodgy GB.

If it is the clutch making the noise, then there will be a big effect on the noise when the clutch lever is pulled/let out.

Of course the noise might be from a more critical part of the machine and a sudden failure might be dangerous to the rider (See recent post of sudden breakage of the paralever!

Your choice!

 

[gabriel_gs]

Pulling the clutch in doesn't seem to make a difference - the noise is still there.

Am hoping I can get it up to Steptoe asap.

...without killing myself!

 

[cabby]

Pulling the clutch in doesn't seem to make a difference - the noise is still there.

Am hoping I can get it up to Steptoe asap.

...without killing myself!

Does the noise change sound/pitch depending on what road speed you are doing? If there is a relationship between the two, it is probably the GB, a thrust bearing or similar. If the noise increases with engine revs it could be connected to the clutch, although youve said that pulling the clutch doesnt make a difference. Noises that can be connected to clutch lever operation will be thrust//release bearings. Is the clutch slipping at all after gear change?

 

[gabriel_gs]

It doesn't seem to change with revs (at least when in Neutral) - will check tomorrow when I ride it how it differs when in gear, but pulling in the clutch also doesn't seem to make a difference.


First time I noticed it was yesterday on the motorway, accelerating away hard, probably in 4th or 5th gear, so seems to be there throughout the gears.

 

[pablo666]

......First time I noticed it was yesterday on the motorway, accelerating away hard, probably in 4th or 5th gear, so seems to be there throughout the gears.

Just to add to the frighteners
Big end noise? (Often apparent on hard acceleration)
Piston Slap?

Ran out of oil recently?
Hi milage bike?

 

[Dragon Master]

What model/age is your bike? Somebody said above about riders doing thousands of miles on a dodgy gearbox; I'm one of them; I did 45k on mine after it started rattling. But that was/is a '95 box with tapered roller bearings on the input shaft, which were knackered. I've recently stripped a /97 box with knackered ball bearings on the output shaft. the bearings had fallen apart, and the shaft end had become tapered. The guy I got the box off said it made some awful noises, a bit more than 'rattling'.

What about pulling the clutch in when the bike's on the centre stand? Mine rattled with clutch engaged, quiet when disengaged, which told me it was (most likely) the gearbox, as it turned out.

Dave.

 

[gabriel_gs]

Ok here's as full a description as I can muster (with my limited mechanical knowledge!)

1) Noise is like a rattle - without knowing what's in a gearbox, I'd say it's as though 2 spinning or vibrating metal parts are occasionally touching

2) On the centrestand, when in neutral, the noise occurs whether the clutch lever is pulled in or released.

4) On the centrestand, with the clutch pulled in, the noise is still there regardless of what gear I select

5) Riding, the noise seems to disappear when the clutch is released (bike in gear) and revs are over 2k - so no noise when I'm riding along, though I can detect it slightly below 2k revs when in gear

4) Gear changes seem unaffected

5) bike is 03, 1150GS with 35k miles on it and to my knowledge hasn't had any clutch/gearbox work done to date.

So, with my limited knowledge, I would guess it's something to do with the clutch, but as I say I have no idea of the inner workings of clutches/gearboxes etc.

Again, thank you for any advice!

 

[Dragon Master]

Right, from what you just said, I'd say that the good/bad (delete as appropriate) news is that it's unlikely to be the gearbox. If the clutch is pulled in (disengaged), the gearbox isn't turning (try it again while you hold the rear brake on, just to make sure. They can sometimes 'drag', even in neutral, so can't be making any noise.

That's my interpretation, but I ain't the greatest at mechaniching; Steptoe is probably your best bet...

 

[gabriel_gs]

Yes indeedy.

Got it booked in with Mr. S for it's 36k service monday week and I'll hope to pop by tonight/tomorrow to give him a listen - just in case he thinks it's something I should't ride on till then!

 

[Steptoe]

Looked at the bike today and it's the clutch slave cylinder that's gone tits up.

 

[gabriel_gs]

Steptoe saves the day again!

And squeezes in it's service too.

Thanks again!