This is a sad story......mine was very similar with 2 gearboxes, 3 rear diffs, outputshaft, shims, rear axles, front prop shaft, rear yoke, hose leak......im sure ive forgotten something. The difference is i eventually stopped going to land rover and took my car to bruce davis and graeme cooper, and would you believe i haven't had a problem since.....touch wood.
In your case there are a couple of things to consider:
1) the lemon laws protect you as a consumer even after warranty expires. Any recurring issue that happens after warranty period that was not fixed during warranty period needs to be fixed by your dealer. If they dont you have been sold a faulty product and are entitled to a refund. I suggest you google nsw lemon laws and do some reading. I have used these in the past with LR australia to great success.
2) a LR experienced mechanic makes a huge difference. You need to get the vehicle serviced by people who own these vehicles and travel all around australia in them. Their experience is worth every dollar. I have no affiliation with Bruce Davis or Graeme Cooper, but having gone through a terrible experience and almost buying a toyota i can tell you they saved my car and couldnt be happier today.
Defenders are a great beast in that some have to be conquered to be enjoyed. It should not be like that when purchasing a new car, not in todays age but once sorted the vehicle will last a long time.
Good luck my friend
2.2 110 limited edition, Davis remap, intercooler, exhaust, terrafirma 30mm wheel spacers, snorkel, first four bb, apt tree sliders, apt diff guards, terrafirma rear bumprettes, mantec rear wheel carrier, Uniden UHF, hema HN7, roof rack, custom made rear draws, dual battery setup, hella ralye 4000 xenon lights, Engel fridge setup, puresine invertor.......coming soon upgraded suspension, diff locks and 33s, nearly finished......

