Hi there, well I'm in kind of a problem with my gearbox.

I was shifting it in kind of high rpm and when I put it in fourth gear it got grip for about 1 sec and the the 4 gear was gone. Now when I shift it into fourth it's no grip, just like in neutral. No grinding noise, no weird breaking noise, no noise at all, just like the fourth gear was taken out of the transmission ...

any help much appreciated