That you have installed it in the front axle with out some sort of disconnect or manual hub set up, I think you'll find you won't like it. If you have a center axle disconnect, use it, if not, you'll need to find a manual hub conversion kit.
I've heard a lot of folks say they don't hear anything from their aussie (and some for lockrites for that matter) but wouldn't be too terribly concerned with ratcheting noises from a rig with auto hubs. If you hear any inconsistent noises (i.e. clicking or ratcheting while driving straight forward, etc) then I would be more concerned.
Also, don't be surprised if the noise fades after it has been worn in "nice and deep-like". But like I said, inconsistencies and big signs should show up before it fails or goes ka-boom.
i have a lock rite in my non disco 30, and i hear it ratchet in tight turns, but i would be a little more concerned if it made a loud noise like described
I haven't heard my aussie in my vaccuum disco 30 but then again my has only had trail use and even then was limited by boggers ability to grab brake lines and break them and then my mistake of not setting the retaining clip fully on my passenger side u-joint and sheering a yoke.
A rachetting sound is pretty normal. I have a buddy who calls lockers "chicka chickas"