Great Post.
I have a 2L TD4 and recently started feeling slight vibration that wasn't there before, checked all mountings, bearing play, even tyre weights then caught this thread. did one up wheel test with 1.2m bar and 5KG weight. took over 6 minutes to drop from 45 degrees to horizontal!! My un-expert opinion tells me the VCU has virtually seized so can't drive the car in its current condition as understand this can screw everything that is expensive. Can i remove rear prop just until i find a replacement VCU
Sounds like it probably is seized, but maybe worth repeating on another wheel, just in case you have a binding brake. What happens when you try to drive it slowly in a circle on full lock, forwards or backwards? Does it feel OK in a straight line, but like the brakes are binding on full lock?