Transmission Fluid

[FordTruck]

What kind of transmission fluid does a C4 take that came out of an 80's Ford F150? I put two quarts of Dextron 3 in it just so i could start it., but before i fill it i wanted to make shure its the right fluid.

[averagef250]

Doesn't matter, MD3 works in everything. It's about all you can get today anyway.

Type F and FA were used supposedly because ford trannies used different seal material. Any auto that has been rebuilt in the past 20 years has modern seals in it and doesn't care what the fluid is. If an auto hasn't been rebuilt in the past 20 years the seals will fail soon anyway so don't worry about it.

[sideoilerfe]

Just don't mix different types. I changed a radiator once and added type F to the C6 transmission because I figured it had type F in it already. It shifted funny from that moment on. 5 months later, lost 2nd gear.

Another instance, I was low on fluid in another truck with a C6, and the store had only drexon, so I put in two quarts and less than a mile later it slipped really bad on the freeway (like it went into neutral). Pulled over and revved it up a bit through all the gears and it caught enough to get home.

I'd say just drain all the fluid AND the converter and you'd be fine with either.

[FordTruck]

I put new front and rear seal's in it before i installed it. Ok i guess i'll run Dextron 3 in it because that's what i already have in it.

Sideoilerfe someting really similar happended when i got my 70 we made it from OK to AR then i lost drive and we went and bought some type F and we crippled it the rest of the way to MO. Then after that my FMX would never go into gear for more than a minute,but reverse awlyes worked

[averagef250]

The fluid type has far less to do with it than people think.

Think about this: The usual scenario is you find out your tranny is low because it starts to slip, so you add some fluid, adding cold fluid cools the tranny down, making it work better momentarily. Then it gets worse again and quickly stops working once you drive it a bit. Slipping clutches fry in seconds. Once they slip, the tranny is done. The other misconception is that the clutches slipped because they were worn out. The clutches would last almost indefinitely if the drum seals that hold pressure to the clutches never leaked.

When you pull an auto down that slipped in a a certain gear or range you almost always find the drum seals or bores themselves for the slipping clutches totally shot. Many times several inches of a 4-5" OD seal lip are completely gone.

The C6 in my 74 ranchito is from a 77 LTD and has never been rebuilt with a lot of miles on it. I pulled the pan, dumped the metal and washed the filter out. It's running on about a 50/50 mix of old type F I had laying around and MD3. It works just as I'd expect it to for a 30 year old auto that I hammer on, it's slow to shift cold and 2-3 shift is getting pretty slow under full throttle. I hope to get another 30-40 miles out of it before I have to put seals and clutches in it.

[Chaseman]

just for some input i run type F in my Cruise O Matic in my mustang , I can even chirp the tires going into second if I'm really gunning it. Also it has not been rebuilt since the seventies from what we know.
And you do NOT what to know what that tranny has been though on accident.

[Hawkrod]

The type of transmission fluid you use is critical. Older Fords need Type F or FA. The reason for different fluids among manufacturers is because the transmissions were design with different characteristics and designs. Ford transmissions used a specific clutch material that can't handle the "slippery" characteristics or Dexron and by the same token type F fluid in a turbo 400 with remove all the friction material from the clutches because it does not allow as much slipage. Almost all ATF is made from mineral oil and the differences between them are the additives. In this issue it is the friction modifiers that are most important. Modern replacement parts are usually manufactured using the same friction materials which is why you can use modern fluids in rebuilt Ford transmissions. Unfortunately rebuilt Ford transmissions may not perform as well as they could as the spring loads and adjustments specified in the shop manuals were based on the the original friction materials and lubricants. Most larger or more experienced transmission shops now take that into account when using different friction materials, it is really the small timer or the do it yourselfer who ends up running into trouble down the road. Hawkrod

[averagef250]

The only ATF I can buy from my suppliers (two large wholesale outfits) is MD3. It's not even called MD3 anymore, it's just ATF. Period. In order for the stuff to be compatible in the newest autos that spec MD5 or something else they sell additive bottles that are mixed in at a small ratio to the "ATF". There is nothing even offered for type F.

I know you can still get type F on the shelf at many parts stores, but it's soon becoming a thing of the past. It is no longer on the shelf at any parts store in the town I live near, but Napa does have a small stock behind the counter.

[Chaseman]

Cool I'm lucky then cause it's everywhere in my town. (Bi-Mart, Fred Meyers, Shucks , Napa , The Dalles Auto Parts , K Mart.

[Joshpow]

I found my Type f in a little local market doen the road from my house. I was on my way to town and stopped in for gas. Checked the tranny fluid for some odd reason, and found it was a little low. Checked their shelf to find several bottles. It didn't appear to be old bottles either, so someone must still make it.

[Jake11]

If ya want it to slam, use type "F". Dex will make it slide. Ford quit
using type"F". If you pour Dex in a older Ford, it will slide to death.
All the frictions now are made to work with Dex. Jake