Disco 2 clutch Judder

Could anyone offer assistance. I have a 2003 Disco 2 which has a judder ever since a main dealer replaced the mainshaft oil seal. It has been back into them and they have replaced the complete clutch, Flywheel and the release bearing and it still has a judder. They are now saying they are all out of ideas. They have backed off the transmission brake and ensured that the hydraulics are ok. HELP PLEASE!!!

they've overlooked the spigot bush

to confirm it, start the engine and with it idling, just rest your foot on the clutch pedal, if you can feel a vibration through the pedal then thats what it is.

when the vehicle was being built at the factory and they assembled the engine and box together, the clutch wasn't quite lined up but the machine just forces them together and this damages the bush, normally they just make a noise when cold but somtimes they can be so bad as to force the mainshaft to run at an angle, this will be why you had the oil leak in the first place

Thank you Clutchdust