Causes of take-off juddering other than SMF clutch?

[4door4]

If a mk6 transit has juddering on takeoff, but the juddering feels the same in both 1st or 2nd (or reverse) and regardless of engine rpm, could it be something in the propshaft assembly causing it? If a single mass clutch is causing juddering then wouldn't the juddering get faster when the engine revs increase while releasing clutch?

The van drives nicely on the road with no vibrations once the clutch is fully released. Smooth all the way to motorway speeds. The splined connection in the prop shaft looks to be aligned so the UJ knuckles are in-line and not fighting each other. There would be two possible alignments 180 apart I suppose, if that matters. Any other things to check?

[dumper]

Maybe oil leak onto clutch plate

[Jim Archer]

RWD?

As above, or shagged gearbox mount.

Jim