Unexplainable Transmission Stutter... help?

Doc - seems like you have covered everything pretty good so far, while its still a major mystery, since you changed both the external cooler and the lines check them both to make sure they are clear, also check the fittings at the transmission. I still have more to learn about the pressure effects on the trans but maybe a plugged line or cooler could be the culprit - I have seen things like coolers that didn't get the shipping caps or plugs removed before install and it really sucks

good luck