New noise in 4wd....

[dom14]

Well, there's growls and there's growls so without much else to go on...
I would hesitantly suggest it is possibly an outside chance of maybe being a universal joint or a CV.
When they first start to crap 'emselves they can go quiet under load and only get noisy when coasting.

That's what I thought as well. Since the growling only happens when coasting, it points at the diff centre or the uni failure at early stages.
See if there's any play in the front uni joints. Not sure how to externally diagnose shot CVs. I've never done it or had any problems so far. I'm sure the forum search engine might produce some good links onto that. Search for the symptoms of the failing CVs. It's a greasy job to replace them. So, it's a good idea to know beforehand for sure, if you are planning to DIY replace the CVs.
If I recall correctly, go through MudRunnerTD's threads. He's done a detailed documentation on CVs.