I have an idea the transmission bushing is worn, but not that much. Car has 150 000km on it.
I am grabbing it by the propshaft yoke to see how big the play is at the transmission bushing. It is at a guess 2mm play if I try and wiggle it.
I am tempted to say I think it is the propshaft that is out of balance and/or the uni's that are also worn.

There should be no sideplay. Play at the output shaft of the transmission can be caused by a worn transmission bushing, by a worn propshaft yoke, or by a bad u-joint.

A slight bit of play will not cause heavy vibration.

Mine did that but it was @ the other end. The uni joint was buggered

Hi all
The part where the propshaft goes into the gearbox, must there be a small sideplay or must it be rock solid without any side movement.I'm trying to figure out why my car has a vibration if I go faster than 110km/h. The faster I drive the heavier it begins to shake. At 150km/h it shakes heavily and then I back off quickly before I break something.Thanks