disco tdv6 HSE auto box judder

hi all
i have a 2005 Disco AUTOMATIC with 90k on clock . Recently started "juddering" when under load on hills in 3rd or 4th gear especially towing . The cars been serviced at landrover garages all its life . Guy Salmon checked over and cant find a problem with it . I have heard it might be torque converter or transfer box

Anyone any ideas

If a trained Land Rover mechanic in a fully equipped workshop has looked at your disco and not found any thing wrong the what can I say. Perhaps go to another dealer and try a D3 owners club with your question.