Removal of Rear Diff and Drive Shafts

I am trying to trace a whine in the transmission on my 2001 commercial.

I've done the usual, swapped tyres and taken out the prop shaft and vcu but the whine / drone is still there.

The next stage is to remove the diff and drive shafts to see if it is these or the wheel bearings.

Does anyone know if it is safe to do this and drive the vehicle whilst the diff is out.

I can't see from the RAV cd that removing the drive shafts would have any effect on the preload of the hub bearings.

I hope someone can answer this question.I would never have considered/thought it were possible to drive without the diff or rear drive shafts.
It would be very handy if I could whip it out and fix the leak or find where its leaking and order the parts needed and drive it safely until diff is sorted.