Fendt 512c 3rd and 4th powershift problems

[Favorit 512c]

Have a fendt 512c with 10500hrs on it and for the last while when your in the 3rd and 4th powershift gears its seems to unselected the gear and then go back in again, this will happen every few seconds , it will do it when the tractor is both hot and cold and then the odd day it will go a few hours without any problems.
Just wondering if anyone came across a problem like this before thanks.

 

[GHuggins]

I had 4wd doing this on a different tractor - was the solenoid getting hot and not keeping the electric hydraulic valve in position causing it to jump in and out of gear every few seconds "almost felt like a fish bite or gas engine misfiring" then like yours on the off day it wouldn't act up at all... Don't know if this is your problem or not, but worth a look.

 

[Favorit 512c]

Thought it might be something like that so I swapped around the electric part of the solenoids but it didn't make any difference, probably would have been to easy a fix for it. Also checked the wiring for it an all checked out OK.