Front and rear diff questions

[rollo ford]

Hi all,don't post much so please excuse me for asking a technical question.
I have a 96 3.0 diesel auto surf with around 96000 miles on it.
Had it almost 2 1/2 years and since I got it there's been a whine/rumble from the front end,only I noticed it just at first but it's gradually got louder.
I recently had the diff oil changed and the o/s wheel bearing changed and it's getting louder and a lot more noticeable.
When the oil was changed there was a little bit of metal in the oil but the garage said it wasn't bad enough to cause concern.
My question us are the front diffs known for going at low mileages?
Mine is never off-road but does do a bit of towing on the road.
Are all 3.0 front diffs the same ratio so if I buy from a breaker to keep me going I'll have no issues with gearing?
The rear diff is fault free except when I'm coming out a junction and need to accelerate I find it spins whichever wheel goes light far too easily.
Is there a limited slip diff I can buy which keeps a bit more lock before allowing a wheel to break traction?
I read a thread on here about a guy importing diffs from oz for around £600 which seems reasonable.
Thanks for any info,rollo.

[Growler]

Are you sure it is the diff going and not the bronze bushes in the hubs ?

You can get the diff code from the vin plate to make sure you get a matching ratio if you need to swap out.

[rollo ford]

Are you sure it is the diff going and not the bronze bushes in the hubs ?

You can get the diff code from the vin plate to make sure you get a matching ratio if you need to swap out.

Not sure about that,it sounds more of a full rumble than a high pitched whine if that makes sense.

Found a diff on evilbay for not much money,tempted to try it to see if it helps.
The mechanic who is really knowledgeable on all 4x4's never mentioned bronze bushes being worn when he replaced the n/s bearing so could you tell me how to check and I'll take the hub apart if needed to inspect them.
Here's a pic of it with my trailer,the surf owes me nothing and I use it every day for anything,cost me £45 in 2 1/2 years in repairs.

[rollo ford]

Been reading a bit about the bronze bushes and looking for replacements but Milner and jap parts don't list them for my surf.
The other threads I found about them the noise they mention sounds like what I have.