Hi guys.
Thanks for the replies.
Here is more information.
My driveshaft was little bend when my clutch was replaced.
The good mechanic I used to do the correct clutch replacement took the driveshaft to an engineering place.
He said he stood with them when they bend it straight and balanced it again.
It is definately not speed related.
Only revs related.
If I do it in 1st and second gear it does the same thing in both gears.
In second gear at 6000rpm I get 100km/h.
My universal joints are also brand new.It was replaced and fully greased a year ago.
Has not too much miles on them.
Can it be the flywheel being out of balance?