I'm going to be changing the oil in my tranny and rear end today and I was wondering what kind of oil to use. I know that the T56 calls for ATF fluid (god knows why ) what band is recommended, I don't want anything too too expensive. As for teh rearend, what weight gear oil do I need and what brand is recommended? Whats all the talk about adding limited slip 'additive' is that really needed?

 

yea, just use some quality atf fluid in the m6
just change it at the required interval and you'll be fine, no need to go overboard putting expensive stuff in there as long as you change it when it needs to be done
4 qts is needed for this

for the rear end, 80w-90 is what is reccommended in the owner's manual
just pick something and put it in there also
and the limited slip additive is a MUST
just go to your nearest dealer and pick soem up, they'll know exactly what you're talking about, it's about 8$
you'll need 2 little bottles of fluid for the rear end and you'll be able to get about 1.5 to 1.75 in there

have you checked brent's site on this lately?
http://www.bfranker.badz28.com/fbody/lubeoil.htm