Are lsd diffs supposed to be a bit noisier than open ones?

[petroscf]

I had a whine which was way louder under load with my LSD and it turned out to be the ring and pinion

So you mean that the whine was also present (not so loud) when no gas pedal was pressed - but way louder under load, right?
Do you remember, what happened in cases without load but: 1) with gear plugged in, 2) if you pressed the clutch or unplugged gears (neutral) ? Could this give the answer?

[Jeroen]

The noise was always there as far as I can remember, just very slightly. But if its not real loud I don't think I would bother doing anything about it.

[petroscf]

Yes, I am trying to define loudness levels....
Sure thing is that before re opening diff housing and/or gearbox, I 'll have to decide first... And sure I need to turn up the volume for some time...