Well, since the rear diff gasket is reusable. I went and changed it out. The fluid in there had only 7,100 miles on it and it what a nice charcoal color. The magnet, in the bottom of the diff under the ring gear had a bunch of fuzz on it. I tried to take it out but further investigation shows that it is RTV'ed to the bottom of the diff, so I let it alone and cleaned it up the best I could.
The 10mm diff cover bolts where on there pretty tight. I couldn't loosen them with a 1/4" ratchet. I had to use a 3/8. Plus the lock tight that was on them was holding strong. I had to use the ratchet to get them most of the way out. I couldn't loosen them by hand.
So I cleaned it all up, put the cover back on and snugged the bolts back down. Filled it back up with 2qts and 24oz of AMSOIL Severe Gear 75w-90. This pretty much filled it until it started to drip out the fill hole.
Oh, before I started I took the fill plug out and a little fluid ran out, so it was serviced correctly and so that is where I put it back to.