have searched - please help

hi
im having a bit of trouble with my disco td5 manual
i keep loosing 1st & 5th gear - this happens randomly, sometimes it wont go in to first but if i do a second gear pull away & stop first gear comes back - also lately having the same problem with 5th - its almost like the gears are no longer there, when trying to select fifth for example the gearstick wants to go in to the third position - yet the next time i drive it - it may work perfectly
i assume its a selector problem - is this fixable or is a new box needed ?
sorry to have to ask but i know very little about transmissions
hope someone can shed some light as i do not want to replace the gearbox unless needed

many thanks in advance

If you move the gear lever from side to side is there spring resistance both ways?

yes there is

maybe the plastic railko bush or yoke are gone, or bias plate cracked you'll have to get to the bias to inspect, see parts 6 and 4 here http://www.allbrit.de/UNI.cfm?PAGE=817378&SPRACHE=EN and 9 here http://www.allbrit.de/UNI.cfm?PAGE=817237&SPRACHE=EN , this one is underneath the others

wow i wasent expecting that - guess what im doing the weekend

thanks sierrafery nice one