It's a cable clutch. Clutch feels fine when driving. Bites when it should, disengages seemingly without drag.
Gear oil has been topped up with 75w90 this weekend, but we didn't manage to extract the old oil. Last drain was 4y, 15000km ago.
My guess it's something with the synchro's or forks, but shouldn't that affect only some gears?
Note: The engine has been swapped 2y ago and only recently got the correct ecu. (Long story) The gearbox never saw more than 140bhp at 6500rpm before this winter, now it takes 160bhp and 7200rpm. Could it be a matter of running in?