I think I've sorted mine. The handbrake drum was not getting centralised on the output flange when it was tightened up. So it was sitting off centre. I've loosened the propshaft bolts, centred the drum and retightened the bolts. Now it seems to run OK without binding.

I've got the same sort of problem and I'm fairly sure it's the handbrake. The chirping varies with speed and gets louder if I pull on the handbrake a bit while driving. There's also a judder/pulsing which would fit with the drum binding for a bit each time it goes round. It's as though the...