i got an XR8 AU II 2001... there is a big '' clunking'' sound in the ars end when you are taking off or just putting around.. i have had the diff rebuild, thinking the star gear had been flogged out. but all was good. i have had the rest of the ars end inspected by ford and diif places and no one has a clue... just wondering if anyone has had a problem the same.. or any idea's for me.. i have spent thounds trying to find this boodly noise.. any help would be great as i am all out of idea's.. cheers

If its been checked by diff joints its not likely to be this, but I've had a phantom cluck that was loose tail shaft to diff flange bolts

i got the exact same noise, pisses me off..

Not the exhaust hitting the body? or diff ?

have you had youe suspention looked at?
reason i say this is that a mate of mine put some new shocks in his bombadoor and had a terrible bang like yours.
reason,he had put both rubbers on the bottom of the shock.

change the diff oil and add some of the anti-chatter additive as per factory specs. Some of the newer diff oils aready have the additive in there, as ford/h*lden have had similar issues with diff clunks. Do a few left hand and right hand full lock slow circles (slow..) to distribute the stuff around. The NEWER Penrite 10/10ths and the 80/140 Castrol SAF-XA have the additives (75/140 saf-xa and earlier Penrite do NOT have the additive, but Penrite do sell the additive seperately.)
Do not dismiss this until you have tried it - I was lucky and did this BEFORE going to a diff place. In slow Peak hour traffic, the clunks were REALLY bad... after treatment as above, its quiet as a mouse.
let us know how you get on.

Had the same problem, turned out to be shock mounts were broken. Then the diff got rebuilt and all was good.

Took the diff out and back to the bloke who rebuilt it.. he adjusted the
clearence's and said the diff was in perfect condition.. so i though it back in and added some Lx-3 modifier and Castrol LSX-90 and done a few circle's around the yard. not a sound... u can still here it very faintly and does the odd clunk. but has emproved 100%. i don't think this will be the end solution but has solved my problem for now.. thanx

i wld say the diff has excess backlash get new spaces for it and it should be good as gold