1566 shifting - really hard upshift, easy downshif

I did the clutch free travel, trans. brake and T/A dump valve adjustment, as per the service manual and also tractor vet's instructions here on this forum.

I checked everything over several times. I can go through the adjustments with my eyes closed now :)

Shifting from 1 to 2 is very hard and needs a lot of 'work'. 2 to 3 is also hard. 3 to 2 and 2 to 1 is always easy. So, upshifting - hard, downshifting - easy.

Once the tractor is in gear, no problems operating. Shifting between H, L, N and R is easy.

Shifting seems to be easier (marginally) when the transmission is cold.

One other thing I noticed is that the clutch is about as hard to push when the engine is running as when it isn't. Clutch is (supposed to be) hyd. assist. Could that be the problem?

Could it be that the clutch is not disengaging completely?

Could this be anything else other than the clutch/brake/ta adjustment?

Looks like the problem is with getting it into 2nd gear. I.e. the problem is with the 2nd gear itself.. Am I looking at a major repair here?