I have been having some slight transmission/vibration and slight shift hesitation. In the manuel it says atf-z1 or if not available Dexron III. I am looking back at my 90K service and noticed the ATF fluid used is Dexron 6. Im kind of thinking that I did not have the problem before having the service that included replacing the transmission fluid. My wife drives the car and she tells me nothing. Do you think this could really be the cause? It is a very reputable Honda/Acura only shop.