Land Rover Repair: changin gears in disco II, land rover specialist, torque converter

Question
I would like to have an expert opinion on how the gears should change under normal driving. The first three gears seem to change at normal speeds/RPMs based on other, non LR, vehicles i own. To get to 4th gear, I have to get up to almost 50 mph to get it to change. Driving around town is usually in the first 3 gears and upwards of 2000+ RPMs. The LR doesn't seem to mind. I just wanted to check and make sure this was normal. Its a 2000 Disco II D

Answer
Fourth gear should engage at about 30 mph, but the torque converter lockup should engage at 50 mph in 3rd or 4th.  If you are driving around at 30mph and you are at 2000 rpm, it sounds like you may be driving around in second or third gear, which would indicate a tsuck valve body or a governor problem.  Having said that, it is difficult to diagnose without test driving it.  I suggest you take it to a Land Rover specialist or a transmission shop and have them give you their opinion.