26/6/08 - A loud clonk!
I have crawled underneath and pushed and pulled things.
With the handbrake on (so the wheels are locked and will not rotate) and pushing the vehicle forwards and backwards I get the same squeaking and can see movement in the trailing arm bushes and the axle/diff attempts to rotate downwards, creating a vertical movement on the prop.
This video shows the trailing arm bush.
These videos show the prop/diff moving up and down.
So it looks like I need to cancel next weeks MOT and off-roading trip