Howdy all. I am thinking of doing a tranny service on my IROC, and i would like put in Amsoil synthetic. Now i did run a search on their website, and it lists 2 flavors. But i am not sure. I think the spec calls for GM DEXRON II. But that is an old spec, and Amsoil covers the newer DEXRON III and IV. Also how much fluid will i need, for just a service? I am looking at about 10 pints? Thanks.

Well, nobody has any input for me, about tranny fluid?

If the oil looks and smells ok, leave it alone. Otherwise just use the oil you have been using for a service change. Amsoil is an excellent oil, but do a "complete" change if you are going to do this.

Interesting thoughts. i checked my records, and my 700R4 was overhauled completely in May of 2007, but i have only put 10,000 miles on since then. Not sure what oil they put it in, buy maybe Redline Synthetic. I also read that you cannot get all the oil out, with just an in-car service. My manual says 23.0pints for refill after dissasembly, and 9.9pints for a drain/refill. So it looks like i wouldnt get it all out, and would be mixing Amsoil with the old stuff.
For some reason i just have it stuck in my head, that i need amsoil for all the fluids in my car. Maybe i just do the rear-end for now. When i get her in the shop, for 2 new tires, i think i will just have them check the tranny fluid.
After all, Amsoil is not cheap!

Drop the pan and change the fluid and filter every 20,000 miles.

That's a lot more important than changing to synthetic.