I accidently put TYPE F fluid in my TH350 trans. (I didnt know there was a difference) and I want to know it thats causing my transmission to run bad (It is) Ive had some people tell me it could do horrible damage while others tell me it will just do long term damage to seals. Which is true?

 

It will do no damage to anything. It is the same actual fluid as Dexron, with some extra "friction modifier" in it to make up for the early Brand F transmission design flaw of having about 1/3 as much total clutch capability as anybody else's transmissions. Time was, Type F was all anybody ran in racing 350s, 400s and PGs, because it made the clutches hook up harder; we all called it "shift kit in a can".

Whatever is wrong with your trans, it isn't the fluid.

 

Stick with me here as it's kinda long, but I'm directly quoting out of my TH350 rebuild book in the section discussing all the different fluids and additives so here goes. Quote:
"Type F[B]- Until recent years, Type F fluid has been used in most Ford automatics. The high-static friction properties of Type F were once preferred by Ford for their automatics, although the company has since switched to Dextron II. So, what do you do if your Turbo Hydramatic transmission is bone dry and the only fluid available is Type F? If you have to, use it. Don't believe all those tales of transmission disaster when an unspecified fluid is used. By Federal Law, all automatic-transmission fluids must be compatible, with no ill effects to the transmission.
Not that there are'nt differences. You may notice harsher or crisper shifts-harsher if you don't like the change, crisper if you do. As you can see it's very subjective. But don't worry. The change is not permenant. If you want to go back to Dextron, drain the Type F and fill'er up with your favorite GM stuff. In an hour or two of operation, that "great GM feeling"-whatever that is, should return to your transmission." End quote

It used to be a "racer trick" to run Type F in the GM trannies cause it made the tranny shift quicker. I don't know if they still do that, but it was pretty common back in the day. So I personally would'nt lose sleep over it.

 

Type "F" was when there was asbestos in the clutches, which Ford used in most cases before 1978. When asbestos became illegal to use, Ford went to the paper type clutches (like GM). This called for a Dexron type of fluid. This fluid allows smoother shifts (the clutches apply at a more even rate). Ford type "F" when used in GM type applications allows the clutches to slip more until the end of the shift, when they come on all at once, thereby making it seem that the shift is firmer. I would not use type "F" unless that is all you had to use (an emergency). The quote; "By Federal Law, all automatic-transmission fluids must be compatible, with no ill effects to the transmission." This is not true, the compatibility factor is within its own kind only. If you want to firm up the shifts?, then installing a Trans-Go Performance Shift kit, larger boost valves, Corvette servo, etc. will get what you want. I've torn down many a TH350/TH400 in earlier times that had used type "F" fluid that wore out prematurely. In otherwords, it is not going to give you the results you want.

 

Im not looking for crisper shifts. Im trying to figure out why my transmission is acting up (IE weird slipping and shifting problems)

 

As stated before thats what it would do!

 

try putting Dexron in an old ford c6, graet way to trash a tranny

 

So then If I drained all the fluid Including the tourqe converter and thouroughly flushed it out. Then filled it with new dexron could I solve the problem. Or have I done permanent damage now?

 

Your never going to get it all out unless you perform a complete rebuild, and case & valvebody cleaning.

If you want to try to get as much Type F out on your own is to delute it over time. Just get some cheap as dexron, fill her up, and drive her around for 30min. Then drain, and repeat as many times untill you can sleep.
Me; I would probably change it a few times in a month. Dude, I ran a TH350 with nothing but Type F for over 4 years with no problems, and then it burned up But I don't think it was the clutches that burned up. I think I smoked the pump.

BTW: so I don't get any heat, this was around '92

Ron

 

hehe stupid ford

 

um no. i like my camaro, i like fords, also like the older chrysler products. they all have their strengths and weaknesses. but to each his own i guess.

 

There is nothing wrong with what you did. The car I am driving today has a Turbo 350 in it, which I rebuilt myself a few years ago with Raybestos waffle clutches; it has always had Type F in it; it works fine. Of course it hasn't been like this very long, it's only been about 5 years and 60,000 miles, so on down the road a bit once it gets fully broken in, who knows.

You did not tear up your trans by putting Type F in it. If it isn't working right there's something wrong with it. You aren't going to fix it by changing the fluid type.

Forget the fluid. It is not your problem.

What is the trans doing? Have you tried the simple and obvious, like a new vacuum modulator? If not, go get one; get the red stripe version. Do not get any other color; do not get a pink stripe, or a green stripe, or the big black can style. You want a small, gold-irridite finished one with a red stripe. Look it up for something like a 71 Monte Carlo with a 400 4-barrel, that should get you the right one. Then take it out of the box and look at it. If it isn't the red stripe, don't buy it, keep looking up part #s until you find the red stripe one. There's ony 4 possible part #s that fit PG, 350 and 400, so it shouldn't be too hard to find. When you put it in it will probably need some adjustment; there's a little screw inside the vacuum fitting, turning it clockwise will make it shift later and harder, CCW will make it shift earlier and softer.

Check the vacuum line that goes to the modulator, make sure there's nothing wrong with it. If it's leaky it will make the trans hang in low gear forever and then bang into the next gear when you least expect it.

 

i was referring to fords wonderful track record at producing some of the worlds finest automatic transmissions (sarcasm)

they finally realized that they cant build an auto trans worth ****, so they have finalized a new deal with GM powertrain to design a new tranny (they know who does auto trannies) for a new platform....both GM and ford will use the new tranny coming up fairly soon.

i dont hate ford, i like stangs alot more than i like hondas i'll tell you that much. but they cant build a tranny, at least not one that competes with the GM hydramatics or the new electronic trannies

 

ok just so that u cleared things up for me. i was just kidding anyway. i like 'em all. no particular brand for me.

 

what and where is the vacum modulator?? Ive seen a wobbley dobbley black vacum line down by the tranny is that the one your talking about. Sorry I know virtually nothing about trannys.

 

the vaccum modulator is usually on the side of the tranny near the pan, there should be a vaccum line going to it. In a car its absolutely necessary to have one.

in racing only applications you dont really need it though. we used built 400's on the towasaurus and we just dont hook up the modulator.

 

What does it do (other than modulate Vacum)
Is it removable easily and without draining the tranny or anything. Easy to change?

 

ya its really easy to change, there is one bolt that hold it on with a clip, similar to what holds the speedo drive in. you gotta swap it out and pop the new one in quick, because fluid will come out. but you dont have to drain the tranny.

it performs the function that a detent or throttle valve cable does on transmissions that dont have a vacuum modulator. it controls part throttle shifting.

 

Ok so the vacum line is connected to the vacum modulator on one end and what on the other end. Should I go ahead and replace the vacum line. If so what size is it.

 

Very easy to change, one bolt holds on its clamp. Some fluid may come out when you pop it off but the trans doesn't have to be drained.

It's job is to tell the trans how much load the engine is under.... less vacuum = more load. It changes the pressure in certain parts of the trans. The less vacuum there is, the higher it regulates the line pressure to. This pressure operates on the end of the governor valve, such that the governor's spinning tends to move it inward, but the pressure is applied to the end of it which keeps it from moving, which means that the governor has to reach a greater speed before it overcomes the line pressure and moves, telling the valve body to shift to the next higher gear. And, that same pressure is what reaches the clutches; the higher it is, the faster they move and the harder they hook up.

Yes, if there's a vac line by the trans, that would be it. Usually it's a steel one from the vicinity of the carb, to near the trans; with just a little short piece of rubber line. If your car requires the 90° piece of line by the trans, use the molded one that comes with the vacuum modulator, it makes a difference. Regular line will collapse.

 

Yes, in some cases (type F) works with Raybestos waffle type clutches. To do a complete change of fluid the easy way is to drop the pan, change filter if necessary, install pan, remove the transmission line at the radiator and put on a hose into a large clear container, fill transmission with new dexron III, have a funnel in the dipstick tube, start motor and have someone add fluid at about the same rate as it is filling container, once you have did a total of 13-14 quarts, you are done as far as doing a complete as possible fluid change.

 

hehe i pumped 20 quarts of fluid through my th400, and it was still kinda dirty, but i called it a day and its much better now.

that was only the second change of fluid in 160K miles. that 454 and th400 still run the ballz though.

 

Thats a good idea. Ill try changing out all the fluid before the vacum modulator. Thanks.

 

Just to clear up some earlier mis-statements: Type F does NOT have the friction modifiers, while Dexron does. Using Type F in a Dexron-spec tranny would produce harsher shifts because of this, so it "seemed" like a good thing for racing.

The friction modifier in ATF is the same thing used in posi gear lube. It smooths out the engagement of the friction disks, that's all.

 

wanna know what the ultimate transmission fluid is?


laquer thinner.......hehe try this out, put that in instead of tranny fluid....you'll only get one pass....but ohhhh man is it sick

the thinner locks the clutches together on the shift....permanently lol.

 

Ok Im going to do the transmission fluid cycling that was described by Pro Built Automatics.
I just want to be sure which line to the radiotor is out and which is in. So I know which to disconnect. And whats the best way to attach a hose to the end of the line. Any other general tips. Thanks in advance.

 

I take off the lower line and route both into a jug.

A rubber or clear plastic line will slip over the line flare. I have some fitting sitting around to provide a nipple for the cooler.

 

What size fitting will I need to go into the radiotor?

 

you shouldnt need a fitting for the radiator.....you should just have to pull the line out and put a hose on it.