At end of my tether, i have a vibration when the car is under load when at 1500-2000 revs and between 30 - 50 mph. Had gearbox/torqe coverter changed a year ago and took it back last week to be road tested as thought this was the problem again but they said all working as it should. Its had 2 new injectors as 2 were working on half power and big service done. Any ideas what this could be its driving me nuts

Check your brake calipers, the usual place suspects are the rears.

Take it for a run then check for an unusually hot wheel. If you find one that could be your culprit  ______________________________
Simon
______________________________

Range Rover Classic 3.5 efi - Gone
Range Rover Classic 3.9 efi - Gone
Range Rover Classic 4.2 LSE - Sadly gone
Land Rover 110 3.5 - Gone
Range Rover P38a 4.0 SE - Pleased it's gone
Range Rover P38a 2.5 DHSE - Just sold
Range Rover L322 4.4 v8 Petrol - Current