Major Gear box overheating

Hi

I have a 96 300 tdi auto and the gearbox overheats like mad. My dad and I thought we fixed the problem by fitting two addational rads for the gear box (one behind the headlight and one above it). We then cut a big scoop out of the bonnet to make sure air got to them but this hasent stopped it baking in town even though we have a kenlow on the back of one of the rads. The only time it is ok is when you get up into top gear on the motorway and the revs are low enough for the fluid to cool down but you can forget about towing anything with it. The disco has been to africa 3 times so the gearbox is probably tired but we have tried everything and it still overheats so any suggestions would be much appricated

Thanks

oil pump and or strainer/filter shagged. is it physically hot or car warning you it is hot as p38 suffer gearbox overheat lies.
is the oil clean or burnt

Right, think logical, gearbox getting hot.
1 , Something's wrong in the box - bearings etc - change g/box
2 , G/box oil not getting to cooler - check g/box filters - if Ok, change G/box.
I know it's not a great deal of help, but that what it looks like to me

Thanks for the help lads. I'll be having a look at the weekend. Fanatic, we have a temp gauge attached to rad and and gets right into the red but I dont know if its in the right place. Its connected off one of the hoses

Provided the box has not contaminated the oil by braking up, if it drives normally-look at oil flow problems-gearbox filter/strainer or pump

Will do

A bit left field, but what about the rest of the drive-train? Check UJ's, wheel bearings, diffs etc for free movement and that nothing is binding.

Are you sure its overheating. Does the warning light on the dash come on? What's the temp gauge you have lashed up?

I am fairly sure. The light on the dash used to come on but dosent seem to any more but the gauge has gone right into the red a few times which is about 150 degrees c