I've read in ford manuals that the pre 1981 C4 transmissions take type F fluid, but the later model C4's use mercon/dextron fluid. Is the mercon just a better fluid or something very different? Can you use mercon or even synthetic ATF in older C4's?
Trans Fluid I don't have a reliable answer on the Mercon or synthetic but I assume it has something to do with the later models with overdrive and also with the smooth shifting patterns most folks like along with lock-up converters. May have some different additives for longer wear and such. Would like to have the technical answer myself, I believe you could use either in the early ones but may cause delayed or soft shift patterns. I would stick with F in them myself, most racers using powerglides use F in them also for a quicker and firmer shift. To have some fun, get some F at the parts store and at the counter tell the guy you are going to use it in a GM trans. You will get a lecture and even some heated arguments over that one. I am just wondering how much longer the F will be available, I do know the synthetics will keep a more constant temperature in the trans compared to others. Might be the way to go sooner or later, the 5 speed std trans in some later Fords use Mercon lll or something like that in them instead of 90w gear oil. AH, the modern technology we have now days.
while i am not sure which is what, type F will always be available because the older trannies require a different viscosity. (hence the confusion as to which or what) i am also told that mercon will very quickly ruin the old tranny. i don't know if the F is higher or lower viscosity but to my understanding by an ol' ford-tologist do NOT use mercon or anything else in a tranny that asks for type F. as far as availability goes, i work in an auto parts store and my castrol supplier say not to worry ... just my .02
Type F I was told by a transmission rebuilding shop that type F was required because of the seals and gaskets used in that type of transmission. The power steering pump also used type F, and use of the newer trans fluid would destroy the seals. A friend of mine used dextron/mercon fluid in a honda and destroyed the transmisson. So it seems that the chemical make up of the fluid is important to the type of materials used in the construction of the transmission. I will do a little research and post a reply on transmision fluids.
Trans Fluid Found some info on the subject, the F is higher viscosity than Mercon or synthetic. When someone uses Mercon in a older C4 or C6, it will leak past the seals and cause poor shifting, chatter and premature clutch failure. The lock up converters was the main reason for the new fluids so they would engage smoothly and run cooler. The main reason a trans goes bad with the wrong fluid is viscosity difference, from what I gather the seals will not be affected by either fluids unless they are already hard and brittle. Similiar to running 10 weight oil in your engine in 120 degree weather, not enough viscosity to run cool and keep things lubed. The article also stated that using F in the later trans, including GM and Mopar, would cause harder shift patterns and also run hotter which will at some point in time ruin internal clutches and seals. In everyday street driving stick with the mfg. recomendations. Above info was from GAO lubricant tech articles. On a footnote, was stated that ATF is the most complex of all lubricants manufactured because of additives and certain molecular structure.
www.exxon.com Open this link and type tranmission fluids in the search box. The top of the resulting list show a page for type F and a page for mercon. There is a reference in the type F description that mentions not damaging rubber seals. I tried to attach the pages to this post,but was unable to at this point. Tony L
Trans Fluid Thanks Tony, that is a good article. Been using that same stuff in my C4 Fairmont drag car for a long time. Last year had over 150 passes on it and at freshening up took it apart. Looked like new, had to replace a thrust washer and that was all. Running a 350 to 375HP 302 and beating on it hard with 4.86 gears and 15x9 slicks. This board really helps an old guy like me find out info.
most transmission shops will put dextron in your car no mater what it calls for. It is cheaper and they buy it by the barrel. Cheak my past post on this, I changed mine back to F type
One of the major differences between the C4 and the later OD transmissions is the greater rotating gear assemblies in motion while driving the cars, require fluids with more lubricating qualities to reduce wear over the long term. At the same time taylor the shift smoothness to the clutch and band material used. Not directly related is the fact that many cars being computer controlled, do some sophistacated transmission controlling such as retard the ignition timing, drop some cylinder firing and various other tricks all in an effort to give the public the feel of continious flow of power with out feeling the actual shifting. The later fluids are used in manuel transmissons because of there lubricating and low viscosity qualities. The F type will be around for a long time yet. In Europe, there is even a G type that can make a C4 shift even more smartly.
Mercon Dexron is a "friction-modified" fluid, whereas type F is not. If you tranny was designed for type F, dont' use mercon! The reason for the difference is that when ford was first using automatics they thought that people would want a transmission that they could tell when it shifted, and thus used a harsher fluid that had very little lubrication. GM went the other direction, figuring that people would want a smooth acceleration, and thus used a friction modified fluid that allowed smooth shifts. In the mid eighties ford switched over....
I have seen type FA and was told it was a enhanced version of type F by a transmission builder. The difference was compared to mercon II and mercon III. It supposedly will not cause any damage to a type F transmission. I am using AAMOCO type F, which is made by Exxon, or their superflo product. I will try to find a web page with info. Do you remember what brand you saw as type FA?
According to the Valvoline web site, type FA is a replacement for type F. The info sheet for Valvoline type F is located at on hteir site, pick transmission fluid, and the 3rd entry is type FA. www.valvoline.com
