Transmission Fluid - A Discussion

New 02/08/2005

What kind of tranny fluid works best with our cars? I know MERCON 3 is the
factory fluid, and then they came out with 5 which I believe is synthetic.
However, another SHO expert in the area warned me not to use 5; he said he
tried it because Ford says the recommendation to use 5 supersedes the
owner's manual saying to use 3. But he said that with MERCON 5 his tranny
shifted violently and did not behave correctly at all, and it took a couple
more changes with 3 to get it back normal operation. I've also found on the
web site by doing a search that a lot of people use the Mobil 1 ATF, which
is also synthetic I would assume, any side effects from that from those who
have used it? Its about time to get that fluid changed, anyone have any
advice on what to use?

Thanks,

Mike
______________________________________________________________________
Nope. Mercon, not Mercon 3. Ford switched to Mercon V in '98 I believe.
Personally, I use Amsoil Synthetic ATF.
http://www.amsoil.com/storefront/atf.aspx
Paul L Fisher
______________________________________________________________________
I have a big question, how can Amsoil ATF cover so many specs ?? My point is the 6 speed in my 05 is Toyota Type T-IV, there is a TSB that states if someone at the dealership or Jiffy lube, or the Mazda owner who knew Mercon V was what went in the previous Automatics, puts Mercon in the new 6 speed, it will seize the tranny. So how can a fluid cover both if one is supposed to be Voodoo ?? Because the way I read it the 2 fluids are incompatible, so how can one do everything?? Not trying to stir crap, just trying really hard to understand the concept.
John Stout
______________________________________________________________________
I agree. It may meet the government specs (and we know how reliable government specs are!!), but does it contain the other additives to are compatible with clutches & such?
government specs don’t deal with the “secret sauce”: that a mfr may use for proper operation.
Ron Porter
______________________________________________________________________
They switched to Merc V in the Taurii starting in 98. Other models
got switched on different years. I believe there is a chart on v8sho
some place (in a TSB IRC) that shows all the Ford models and what
years use Merc V which is a synthetic blend, and which use the
predecessor.

FYI, the wife's 99 is still going at 105K miles and all it has ever
seen is Merc V at 30K intervals (or slightly better)... Granted it
spews fluid when on the track and behaves a little stupid from time to
time, but with the three track sessions the car has done with he
Factory ATX, I don't think I can blame the fluid for much at 105K.
Really seems about par for and AX4N short of the fluid spewing at the
track. Also don't know how many factory trannies with 80K+ have been
proven to not spew fluid on the track (I'd wager less than a handful).

My recommendations and this is an issue where opinions abound, but I
suggest to not change the type of fluid you are using in the middle of
a tyrannies lifespan. After a rebuild with new seals then pick
whatever fluid you want and stick with that. Different fluids have
different anti-foaming and seal conditioning agents in them. If you
change from one that is probably working just fine to another, that to
me could insert the potential to generate some problems that may not
currently exist.

Factory fill until you do the rebuild dance someday is my motto....
That is Dexron / Mercon III for your 97, I even buy it from the
stealer to be certain I get factory fill. Broken / leaky tyrannies
STINK...

Scott Krietemeyer
______________________________________________________________________
Hmmm You and I have done the same three sessions. While I did chew through a bad decision on brake pads at Gingerman, sorry for the smoke show Paul, I've never spewed tranny fluid. IIRC Christian had that problem at blackhawk with his 99 also? Wasn't it an issue of a tad overfull??

Larry Eck

Contact Information