Hi,
I'm driving a 2000 SWB Manual DiD 385 000km, and have the same noise. I started by replacing the alu crossmember in front of the diff (Parthunt), the two bushes at the back of the diff (OEM), and the two bushes on the arms attaching the diff to the body (OEM), with this out of the way, the noise was found to be emanating from somewhere inside the gearbox/transfer box, this could clearly be heard when pulling it on an overhead with somebody engaging the gears forward and back putting torque on the gearbox. The driveshaft stood still while the noise emanated from the 'boxes somewhere. On top of this, when engaging 4x4 and putting torque on the drivetrain, I get the ugliest sound emanating from underneath, almost like gearteeth jumping, nasty! Now I'm double-troubled. Is it Gearbox, diff, transfer case, flywheel or all of the above and how do you pinpoint the problem without replacing them one-by-one?