Funny you should mention Haldex fluid Joel, thats how i ended up at a Landrover specialist to get the XC90 diff fixed.
After i changed the diff oil twice and added some Nulon stuff, the diff was a little quieter but clearly needed some major work. I read up about the angle gear (transfer case) and the mysterious Haldex and its oil. So i put the car in for a service at the only Volvo dealer west of the Blue Mountains and asken them to assess the "diff noise".
They said they heard the noise but didn't know what it was, and asked me to "monitor" it. This didn't fill me with much confidence. Whilst i was paying for the service, I also asked them about the angle gear and Haldex, and asked them to quote for a Angle gear/Haldex oil and filter change. They rang a few days later and quoted just under $1000 to do it, but also recommended that it wasn't necessary or recommended. Based on the quoted cost of a Haldex oil and filter change i didnt bother asking for a quote to rebuild or replace the diff.
More research on the net, revealed the possible Landrover solution. Apparently the story goes that Landrover offers a diff bearing service kit (true) but Volvo don't (i'm happy to be corrected by those who know for sure). As the diff noise got worse, i spoke to the local Landrover guy, was impressed by his knowledge and booked the car in.
The only issue has been the poor adjustment of the parking brake, but the car is booked in for next Wednesday to get it sorted. The mechanic has been doing some research and mentioned some kind of linkage underneath the console, which needs to be looked at. Any thoughts or advice to give him next Wednesday?