- Feb 5, 2023
I'm a new owner of a '98 Dodge Viper GTS and I want to start her off with fresh fluids. One peculiar one is the manual lists Dexron III for the fluid for the T-56 manual transmission. I'm not sure about her maintenance history as it has 35k miles so it might be original or already replaced with something else but it shifts more smoothly and have experienced no grinding compared to some of the more recent TR-6060s I have driven in Challengers which use ATF+4. From my understanding the Dexron III is discontinued and replaced with Dexron VI which seems to be a mixed bag for versions that used Dexron III. My gut reaction to all of this is using automatic transmission fluid on a manual transmission is odd to begin with and I want to know what I should use. Should I use Synchromesh, Dexron VI, or ATF + 4 when changing out the fluid? I don't intend to drive this car aggressively, I just wanted to be reliable and want to treat her right.