Gearbox locks up...

[Wilmer]

Hello, I need help with my GasGas EC 125 05 that something have hapend with my gearbox...

I can't get it down to neutral or first gear, and it locks up in all the gears exept for second gear. I have split the engine to see if I can find the problem but can't find anything wrong except for a broken washer that i found all the pices for. But that doesn't effect the gearbox when the engine is split.

I took the gearbox out of the engine case to look at it more and everything is in good chape, cant find anything wrong with it.

Here is some pictures of it. It's very hard to get good pictures of the gearbox but I can take new pictures if someone needs. I also got a video but for some reason it doesn't work to upload it here...

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Very grateful if someone can help me

[Anders]

Wilmer,

I cannot get anything out of your attachments.
All links are "invalid attachments".

[Wilmer]

Anders,

Okey, I saw now that they don?t work. Im going to se if I can fix it

5900AD54-2630-4121-9E03-5097FD6B8866.jpg

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I also got a good video of it but can’t get it uploaded on the thread...

A8AC736E-40A1-4D6E-B62E-ED17C5A85E1C.jpg

[Anders]

Now, the images are good. What exactly do you mean by 'lock up'? Doesn't the rear wheel rotate, or is it gear selection mechanism that locks up, making it impossible to select a different gear?

[gasgasman]

If the shift drum is " out of time", the transmission will lock up.

[Wilmer]

Anders,

The rear wheel locks up. You can change the gear but it can be pretty hard. And you cant get it in to first gear or neutral. When you get it in to a gear you can spin the transmission a little bit and then it binds up. And the same thing if you spin it backwords. It’s almost like it is a specific spot that lock up all the time. The higher gear you have the less you can spin the transmission before it locks up.

[Wilmer]

Gasgasman,

Okey, how can I look up if it’s out of time. And how do I adjust that? When I looked at it it seems to be right. All the shift forks is installed correctly.

[(F5)]

Well I'm not an expert but I'm pretty sure all those bits should be inside the engine. That might be the problem.

[(F5)]

It's not practical for most but I've seen people who cut a sacrificial case to load gearbox into. With one end unsupported it's a swine to drive through gears as they only have to skew a mm to bind.
You can then see how much engagement (which is what they were looking for to fight jumping out of gear) or check if gear selectors are bent a tiny bit. Check for telltale bluing or scuffing.
Have you swapped a selector around?

[Wilmer]

F5,

This happend when I was driving, I drove in 5th gear in 50km/h and then the rear wheel locked up.