Cant get diff lock engaged ? Disco 300 tdi 96

Just got the diff stick free as it would not mover to engage the diff lock and it moves freely over but the diff lock will not engage Does anyone have any ideas on what I will need to do to fix it or have had this happen to them?
plz help

Its a Disco 300 tdi 96

Thanks for your time

Does the Diff lock light on the dash board illuminate?
some times letting the vehicle roll a bit might engage it, might even be the level of transmission fluid in the transfer box.

try puting it in to first gear and moveing the diff lock gear stick and see if it will pop in

probebly stuck due to lack of use mine was when i got it spray the linkage on top of the transfer box with silicon spray and exercise it. it may stick in trandfer when you get it in if it does release diff lock and revers about 10 foot should get it out...when you get it freed up use it every now and then stops it re occouring...regards cartman690...

every so often, its a good idea to find some nice loose surface and engage the low range and the diff lock. just to stop it from seizing up.
dont do it on a hard surface.