As I understand it (based on reading various online threads for the past couple years, mostly here on taurusclub--someone correct me if I'm wrong), a few (or just a couple?) years ago, Ford finally decided that Mercon V was OK to use even in Taurus Gen 1 and Gen 2 transmissions that originally called for Type F. Because of this change in recommendation on ATF
, I assume (?) that Mercon V is also OK to use as power steering fluid in these older Tauruses, even though Ford originally spec'd Type F for their power steering fluid too. The original dire warnings from Ford about using Mercon V in their older, formerly Type F-only transmissions, were apparently due to some of these older transmissions failing after people put Mercon V into them, but these transmissions were old enough to have problems that were the actual causes for their failure, rather than the Mercon V. Also, some fluid changing outfits were using the "power flush" technique which some older transmissions can't handle.
So instead of using a power flush (with any ATF
, not just Mercon V), the recommendation here has been to do the simpler pumpout approach using the car's ATF
pump, directing the output of the pump into a container, starting up the engine, and quickly pouring new ATF
into the fill tube until just that new fluid comes out, making sure to keep up with the fluid pumpout rate so that the transmission doesn't go dry during the process. I did this a couple years ago, though I refilled with a new synthetic Dexron III/Mercon (made by Eneos) instead of Mercon V just because I wanted to see how the Eneos would behave in my 1994's AX4S--I was hoping it might improve acceleration and reduce some clunking the transmission had been doing for some time. It did improve these problems, but not as much as I wanted, so I poured in some Lucas Transmission Fix a while later to see if that would help further, but that stuff is so thick that it made the symptoms much worse. To try to fix the worsened symptoms, I pumped out three quarts of that mess and replaced it with Mobil 1 Multi-Purpose ATF
(spec'd for Dexron III/Mercon/Mercon V use), which improved the symptoms almost back to the pre-Lucas state, but soon I'll be replacing the remaining Lucas-infected Eneos with nothing but Mercon V, and I'll probably be fine.