why would you be looking in at mounts for 2nd gear fault,only 2 things can cause that ,clutch not clearing but if goes in 1st and reverse stood still not clutch ,2nd gear baulk ring worn so that cone isnt braking on gear thus matching gear and synchro speed hence grating as doing different speeds when contacting ,2nd gets greatest stress so unless others get ptrmature failure 2nd goes first,whirring is worn brgs common at same time can and often caused by debris from baulkrings etc going round brgs ,why i would change oil frequently,fix it sooner than later as will go bang big time eventually as when front brgs go it buggers input and lay shaft and case