When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Diff takes two quarts of synthetic 75w90. To drain, there is a nut on the bottom of the diff (13/16th socket I believe but am not 100% sure). The fill plug is on the back (10mm hex). You will need some sort of hand pump to get the oil up into the fill plug. It really takes about 1.75 quarts until oil starts coming out of the fill plug, which is full. The job is really pretty easy.
It also takes a bottle of friction modifier (slip-lock modifier) unless your fluid comes with this pre-added. The AMSOIL gear lubes come with the friction modifier in it (and I don't use it).
Everyone has an opinion on this one RedLine, AMSOIL, etc are popular.
After researching diff & tranny fluid I went with RedLine... Ordered off the web & took it to a local shop to change it out for about $50. Manager had previously owned 2 vettes so I felt pretty safe!