I have a problem with my 03 manual rx8 LSD diff.

I bought the car a few months ago and and it was running great although there was a bit of play in the diff, you could hear a clunk when changing gears sometimes even when I tried my best to shift smoothly.

The LSD seamed to work great and do its job as it should, only ever lost traction in the wet a few times and it bounced back like it should.

I recently had the diff oil changed with nulon lsd oil, my mechanic said to me that there was some ground up metal in the oil and it was very dirty.

That was a few weeks ago and in the last few days my diff has been playing up. I was driving down a local mountain, just cursing down (no thrashing what so ever, although I could have been slower) probably doing 50 - 60km down long sweeping bends, not very tight at all. My diff didn't seam to like this and around the corners one of the wheels sometimes both of them felt like they locked up. The diff made a clunk and they tires felt like they were bouncing on top of the road, like the diff was locked up or something. It was very noticeable and definitely felt like something was not right.

I'm taking it to a diff specialist next week. Any ideas what could be causing this??

Thanks Ben