Differential Additives?
 

Looking for opinions on differential additives, like Amsoil Slip Lock
http://www.amsoil.com/StoreFront/ada.aspx
or GM's additive sold by Mazdamatrix.

I get a chatter when backing out of my driveway and turning the wheel in the mornings.

I would try replacing the fluid itself before adding anything else if you haven't already. It says on Amsoil's page that their synthetic lubes don't need it, so it seems like just using their 75w90 Severe Gear would do the same thing. I have personally used it in the diff as well as the Manual Transmission and Transaxle gear lube 75w90 in the trans and they work great in the 8.

I don't have any experience with additives like these in the 8 or any car for that matter so I can't say one way or the other if its ok to use. Considereing they say that their lubes don't need it I would assume that it has the same stuff in it so it should be ok.

Thanks for the input. Does anyone know if there would be specific detrimental effects to having too much friction modification in the diff?