I just got a 2000 Honda Civic with 230,000 miles on it, automatic transmission. Not sure when the ATF was changed last, but I know it’s been at least 60,000 miles. My dad is concerned that if we change the fluid now, it could cause problems later due to varnish and build-up becoming unlodged, and damage the transmission. Would using Trans Tune eliminate (or at least drastically reduce the chances of) that problem from happening? Please note that I am currently having NO problems shifting gears. And last I checked, the fluid is for the most part brown with a reddish shine.