Limited Slip Carrier- how can you tell if it is going bad?

I get some odd noises in the rear on my SS, and suspect the LSD based on some similar posts on LS1Tech. It is sort of a rattling marble-like sound from the rear. I will have to experience it again to better describe when I hear it.

 

The axle may need a change of oil and the GM additive, then drive it to a parking lot and do figure-8's to mix and lube the plates.
The other test is jack up one rear wheel, trans in neutral, and with a torque wrench on the lugnut of the jacked-up wheel, if less than 35 ft/lbs of torque rotates the wheel, replace clutch pack.

 

It's a trick question.
His Torsen LSD (standard on 1999-up models) doesn't have clutches, doesn't use an additive, and doesn't need a work-in procedure.

 

Actually the Torsens *do* use an additive as recommended by GM:
Torsen General Frequently Asked Questions page

But you win the prize as they don't have clutches -- so the sound in question is just the gears releasing?
http://www.tacreationsusa.com/differential_carriers.htm

I have to try to find that LS1Tech post with others mentioning the sounds.

 

With the Torsen, additive is optional, not required. Using it got rid of noise in a very small number of units, which is why the TSB was released. Using it can't hurt, but not using it won't hurt anything either.
Clutch type LSD's on the other hand, require the additive to prevent the clutches from gumming up and getting "sticky", which makes the rearend go clunk in the turns.
If yours makes noise only in the turns, then what you here is likely to be the unit releasing. But if it's in a straight line, that's not normal nor good.

 

My bad, I did not read the appointed site earlier.
I now read two 4th Gen Camaro's.
As you say, Mod, no clutch pack.
My '00 SS does not click when turning, but it only has 46K miles.