Now and then, since returning from the Cape, I have had a chirping bird under my KJ and have become convinced the problem was the rear shaft uni joints. It's gone in today for a refurbishment: new unis, harmonic balancer removal, and high speed spin balance. The driveline guys had some convincing arguments for the removal of the harmonic balancer, which I have written up in my post on AJOR about this problem. I pick it up tomorrow so I'll let you know how it turns out, or you can check the AJOR post here:
http://www.ausjeepoffroad.com/forum/sho ... p?t=111154