needs rebuild 2nd gear baulk ring worn out usually first to go as gets most stress ,unfortunately the metal from baulkring will have been running through bearings and other parts causing more wear unless youve been changing it very regulary, gth gear probably the same and synchro hub springs come out not allowing it to lock into gear unless gear isable to move backwards due to circlip failure , i would rebuild using new bearings baulk rings and rebuild of synchro hubs ,seals and consumables