I inquired on here a while back about replacing rear wheel bearings and had the same response from a few guys.
It looks like a PIG!!!! of a job
Luckily mine turned out to be UJ's on the rear prop :bow
The rear bearing on my Mav has been the only repair in 20 years that I decided to let the Nissan dealer do. This was a good decision, at the time.:thumb2
This was long before I knew about this club too.
First sign, was oil in the rear nearside brake drum, which dripped onto the inner wheel rim.
They replaced the seal.
A week later... same problem...
So they replaced the seal and bearing, 10 years later still ok.
So in my case, no prior noises or vibrations, oil leak was the first that I knew there was a problem, so if I were you, brake drums off, have a look for gear oil.
Also have you put the correct diff oil in. IT must be LSD oil, Comma do a good one, 2.8 litres for the older cast iron rear diff, around half that for the lower cost pressed steel version.
There are the odd threads on this forum on how to remove rear half shafts, but it involves big slide hammers, fabricated tools and brute force, and that's before you start on removing the bearings.
Could you try the rear axle on a rollling road at your local MOT station?:nenau
If you are certain it might be the diff, second hand ones are available, and you can always transfer the ancillaries, back plates, drums etc from your own to the replacement, if in better condition.