Engine/Transmission (1998.5 - 2002) New Syncros nv4500

[KKunz]

I have diagnosed that there is nothing wrong with the clutch hydraulics and that the clutch is fully disengaging so that leaves me believing the Syncro for 2nd to 3rd is going bad what kind of job is it to fix is there any special tool or can I just buy new Syncros and putt hem in? It only grinds if it is shifted to quick and only does it on the up shift from 2nd to 3rd no problems down shifting if I shift is slow it just falls in to gear. I might try the oil idea how does LSD additive help in shifting?