Originally Posted By: David1
Now I can feel a nice shift between gears.... and its firm and no bang or anything.
Right now, you have 3 quarts of Castrol in there and, what, 6 or 7 quarts of DW-1? As you get more Castrol in the transmission, or as your fluid ratio starts to favor the Castrol, the Castrol fluid will have more influence over how it shifts. It feels firm to you now and "just right"; it may feel too firm with 3 more quarts of Castrol. I'm not saying that the Castrol fluid is or isn't the right fluid for you, just that the transmission's behavior will continue to change as you introduce more Castrol into the fluid mix.
Some say that they can't feel the difference, regardless of the fluid used. And maybe they can't. But I sure can, and it looks like you can as well. That's the blessing and the curse of these transmissions: you can absolutely "tune" the shift feel with different fluids. That's a blessing in that you actually have the ability to firm it up if you like, but it's also a curse to someone like me, who is always on the hunt to find "perfection".