Land Rover Repair: Disco II auto box issue, forward gears, waste gate

Question
Nigel,  I am in Ireland and have a problem with my 2001 Discovery auto TD4.  It accelerates up throught the gears until it (almost)reaches top gear (I think there are 3 forward gears) but it will not go into overdrive/top gear.  Once it hits close to 2,500rpm it will not get above and feels like it is trying to get into top but something is stopping it.  It has just been serviced and engine seems in great order but I am struggling to figure out if I need a new transmission or if there is some valve or sensor that causes this problem.  Thanks for the help, John

Answer
If I understand you correctly, it sounds to me like you have 2 things going on.  If it will not rev above 2500 rpm, that would be an engine problem.  This could be waste gate or EGR problem.  If it will not shift into the top gear, it sounds like an internal transmission fault.  I can't really be more specific than this.