So come on tell all, what caused your gearbox failure please????

Thanks Stoic, I will dive into it.

Hi simonroma, ?????? it's already in the previous text,

the roller bearing on the arm holds the selector drum in the correct position for each gear, like a peg against a star shape.

if the gear change drum is allowed to freely rotate as mine was due to bearing failure, the gear will not be fully engaged, causing either, the full load on a small amount of the gear teeth due to not being locked fully home or a jumping between gears while on the move.

the problem started in the south of france on a offroad camping trip, there was little option but to carry on (less damage would have occurred if i had checked, hind sight is great!) . the symptoms were very similar to Niek's so it's a worthwhile place to start instead of waiting for the gears to get damaged or tearing the engine down unnecessarily

i hope that's a sufficient explanation. ?

It took some time but I solved my shifting problem. Took off the clutch housing and had a look at the shifting mechanism. Everything was working soomthly of course, at once the was a blockage, not visable why. After a while I went with my finger through the oil bath below the shifting mechanism a look what I found:
http://maniacsmedia.nl/imagehost/?di=5BA9
http://maniacsmedia.nl/imagehost/?di=AFB0
http://maniacsmedia.nl/imagehost/?di=57GA
http://maniacsmedia.nl/imagehost/?di=L10K

I have this problem already 20-30.000 km so I thing my gearbox will survive the winter. The bike is not worth opening it completely, already more than 140.000km on the ODO.

Thanx for pointing me in the right direction.

That ie one of the 'dogs' that mesh the gears together. Each gear should have three. Unusual to see one break off, normally they round off on the ends and start slipping out of gear.

Yeah, this one looks new. Maybe it broke off 100.000km ago:YellowCrazy_J8GDC6:

Good find! it's certainly better out than in!

i retained my broken gear and yes it looks remarkably like the gear mine broke up, 3rd, it actually has 5 of the 'dogs' so your's appears to have shed one, very odd. will post pics later of mine for comparison. i guess if you take it easy it might be ok for now, fingers crossed.
oh yeah the gear was less than �20 at the dealer so i guess it is a common fault.

it does need a pull down, tho they are straight forward to work on, a crank puller is as specialist as they get, even that is easy to make plus a torque wrench which reminds me mine was confiscated at dakar airport, bastids

Mine exploded at 27k kms
 

My gearbox exploded at 27k kms, yesterday. It blew up the engine chassis and launched a gear at high speed out of it.
Cool huh? Anybody had similar "issue" (...)?
No warning signs before the dreaded event, and care&maintenance performed regularly all the time before.

http://i959.photobucket.com/albums/a...pshtyovymj.jpg

http://i959.photobucket.com/albums/a...ps7sgeyv00.jpg

http://i959.photobucket.com/albums/a...psgqnnuif6.jpg

Omg!

Wow! Don't think you're going to fix that in a hurry! ;)

I've heard of 3rd gear letting go before, but never anything as drastic or terminal as yours!!