Hello have the following problem. The 3rd and 4th gear could not be switched sometimes. Ball bearings were saved, ran perfectly. I drove 3 hours with a short stop at the gas station. All good. Then I parked on a slope. In addition, it was quite snowy there. Wanted to start after 10 minutes and there was nothing left. The 5th I could get in yet but that was it. Someone then tried to get the lever to idle. It cracked 2 times and the 5th gear is n The workshop thinks it has to be changed the gearbox, however, they did not look at the switch trains nor looked at the top of the cover from the gear shift and looked under. Gear oil drained and then they got the tip to press a pen back and it went perfectly to switch. Oil back in, out of the workshop and it probably only went the 1. And then nothing more. The switch is in idle and it went only the fifth. Can it be that something inside Is there a problem there? Does anyone have a suggestion? Thanks in advance