Ok so I changed out my trans fluid today in my LS with a M6 and I must say its pretty easy, first I went to the dealer and they looked at me crazy because I was wanting my fluids changed and there is only 1500 miles on the car, then he was like alright we can do it but its going to be $140, I kindly told them to screw themselves, so I took it to my buddy who owns a garage and we did it. Now since I have done it I find that its easier to shift through the gates and its a smoother transfer between gears, plus im glad I kinda did it because the V6 requires 1.9 qts and I'm pretty sure I barely got a 1 QT out of it (someone at GM messed up). So if your having problem with stiff shifting try changing out your oil and see if its any better.
Now as far as fluid the V6 uses: 75W-90 Gear oil and it holds 1.9 QTS.
V8 uses: transmisson fluid and it holds 3.65 QTS
The first pic shows the drain plug. Its directly under the transmisson and mine was marked with a green mark on it.
The second pic is the fill plug. Its about half way up and a little behind the drain plug on the drivers side of the tranny.
Hope this helps out my fellow C5 members with the V6
