Outer Limits 4x4 Board

hey guys got a problem again..

i just got a 88 hiline an its been driving round great was testing low range today an now its stuck in 5th it will not disengage fifth at all the clutch n drive operations still work as i managed to drive it back in 5th low some how but even while driving when u hit the clutch it just starts to grind like there no clutch anyone have any ideas???


model details
88 hiline
5spd
lt230t transfer

Will it shift when stopped and the engine off? If so, clutch. If not, gearbox.

it wont change gears weather the car is on or off
but the clutch an hydrolic set up still works fine
i just cant change it out of fifth

im pritty sure it the gearbox but having sed that im not sure ifits a problem with th serlecter or somthing internal of the gearbox
thing that ods me is it was driving fine just prior
an days b4 no noises nothin