Hi there, looking for advice, 2008 fl 99k miles when accelerating get slight vibration and what I could only describe as resonance.the higher the gear andlower the speed worse it gets, took it to lr say it needs low level diff repair which requires final drive seal and bearing, got home took filler plug off diff (no sign of leaks) topped it up took quite a bit to fill it , been running bou a week now still no leaks. Whzt im wondering is there anything else could. cause the vibration. also is there a minimum speed before changing into 6th gear.lr want 660+vat .cheers

On mine the economy warning light that advises you to up a gear when in 5th it comes on at 50mph to advise you to move up to 6th.
So one assumes you dont really need 6th under that speed??

Do you get a vibration at a certain revs? Mine vibrates at around 1800 revs in the higher gears as the flywheel is just starting to go. There are many posts on here about rear diffs and a lot say that rear diff problems are associated with loud noise from the rear of the car. Are you experiencing any noise? Black MY2013 SD4 GS Auto, Wood Company Armrest, Freel2 sticker.
Gone MY2010 Freelander 2 Manual TD4.e S, Alaska White.

When going up slight incline , or inhigh gear and accelerating get vibration stops when I ease off pedal, also just noticed engine rocks about a bit dont know if its connected

I'm no expert but that sounds like it may be a dual mass flywheel on it's way out. Part of it's function is to dampen engine vibrations and protect the transmission from the the high torques associated with turbo diesels. When you lift off the applied torque is reduced hence the vibrations stop. Hopefully someone more knowledgeable than me will offer you some advice.