I've searched and haven't come across a definitive answer yet. My question is what are you guys using for Synthetics in the trans and diffs? I use Mobil 1 in my engine already. What weight syn. can I get for the diffs? I do all my work myself and have access to a lift. Thanks for the help.

I use Mobil 1 or Royal Purple 75w90 for the rear diff. fluid.

Stone

I use amsoil... go to their web site and you can choose your vehicle and application (trans, diff, Xfer, etc.) and order it right there. Its expensive but I challenge anyone to say that something is better. But Mobile 1, royal purple, and red line (i think thats the name) are also very good.

Here is the link to the amsoil site to look for your particular vehicle's application
http://www.amsoil.com/scripts/runisa.dll?amsoiloaf:index