OK, so the dealer I went through has performed warranty work on my AU XR6 as I requested with the RAC Report. Unfortunately the guy who I was dealing with was not at the car yard when I collected the car today, and the other bloke had no record of what had been done.

On the RAC report, it states that the diff has excessive backlash.... I assume that this means there is a bit of play in the diff... some sort of looseness? The RAC marked this as a warrantable item... the dealer or his mechanic marked it as N/A. So I doubt anything has been done to it yet.

At low speeds, say like in a car park in 2nd gear, there is a knocking noise from the rear, and you can kinda feel it a little. If the clutch is pushed in and the car is coasting, there is no knock. Does it sound like the diff is playing up?

My Ba ute manual did the some thing and the clutuh squealed when i took off in first, had backlash when driving slow or when you backed off in fourth gear. and the dealers said there was nothing wrong with it. They did nothing about it. So much for a new warranty.
Paul

did you get it fixed yourself eventually? Im guessing it was the diff?

Im still learning a fair bit of this stuff....

have you got the IRS set up like the fairmonts
if so you'll have drive shafts and this is a common problem
had mine replaced in the au at 2 years old and no differance
just learn't to drive it without making it clunk!
bullshit i know but ford eventually admited they couldn't fix it

No didnt fix it, I just put up with it Korben. I sold it and brought the BF