[4.6DreameR]

I took my dad around for a drive so he could hear the noise going on with my car. As I turn and slow down its a clack clacky clack clacky noise. And it sounds like it is coming from the trans, but he says its more likely the diff. Which would make sense because of the LSD transfering power when turning. Would a different weight oil than from factory cause the LSD to start acting up like this?
I was recommended 80-90 lucas gear oil from a guy at autozone, I picked up a bottle of friction modifier too.(<--mistake listening to anything they have to say)
What is the weight from the factory? 90-130? 75-140?

[MATT02GT]

I believe 75-140 was the stock weight in mine but i doubt the oil would give you the noise. I always add the friction modifier too. But I'd start by putting the car on some jack stands and checking the u joints, suspension bushings, and spin everything to check for excessive play. Might try runing if the car in gear to listen for the noise.

[Eagle2000GT]

My owners manual says 80w-90.
http://shnack.com/docs/2000_owner_guide.pdf

[GP-SE]

75-140 is what the tag on my Diff Cover says

[NickPohlAandP]

Always go with what's in your owners manual (or on your tag on the rear end if it's stock). And also +1 to the friction modifier. When I used to work in a shop years ago I remember having similar problems in an ambulance when I forgot to add the modifier (we had a contract to do all the maintenance for the local ambulance company). I was young and didn't know better, but apparently they type and weight of the rear end oil is very important.