1957 Mixing Type F Transmission Fluid with Dex/Merc

[TJShea]

I had some work done on my new to me 57 a couple months ago, which included work that required the automatic transmission to be drained. . I am pretty new to owning a 57 T-Bird, and having a 50's era automatic transmission, so I am a novice on some related things . The repair tech said that "transmission had been worked on" so Dex/Merc transmission fluid would be appropriate, and that is what they used. Previously, I had bought a couple of containers of type F transmission fluid to have on hand. Today, I noticed the transmission to be a little low. Can I add/mix type F with Dex/Merc, or am I just asking to problems in the future. Hate to just waste the Type F, but I surely Ii not want to screw up the transmission over a couple of containers of fluid.

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[Mrujoint]

I had some work done on my new to me 57 a couple months ago, which included work that required the automatic transmission to be drained. . I am pretty new to owning a 57 T-Bird, and having a 50's era automatic transmission, so I am a novice on some related things . The repair tech said that "transmission had been worked on" so Dex/Merc transmission fluid would be appropriate, and that is what they used. Previously, I had bought a couple of containers of type F transmission fluid to have on hand. Today, I noticed the transmission to be a little low. Can I add/mix type F with Dex/Merc, or am I just asking to problems in the future. Hate to just waste the Type F, but I surely Ii not want to screw up the transmission over a couple of containers of fluid.

In my estimation, the first thing to do, is to find out WHY the trans is low on fluid. Once you have that figured out, I've been told it's not really a good idea to mix transmission fluids. Kinda like oil, you're not supposed to mix synthetic and mineral, and so on. Might consider asking a local trans shop expert their opinion too. Best of luck with you "new to you" 57!

 

[Pink T-Bird]

Type F for the Ford automatics did not come about until the C4 transmission, so late 1963 with the introduction of the '64 models. Type A would be authentic for an original '57 car. However, Type A is nearly impossible to find for the last couple decades. Dextron/Mercon is the most similar in properties to Type A, and is easy to find, so it is what is commonly used, just as your technician stated. The shifts are slightly harder and usually later with Dex/Merc compared to type A. Type F has also become very hard to find as it has been replaced by FA. F and FA are "grabbier" that A or Dex, so will exacerbate the hard shift feel.
I remember from working in a service station in the late 60's and early 70s that there is one direction that mixing A and F can work, and one that will foam like crazy and damage the transmission. Sadly I'm not 100% sure after 50 years which is which. So unless you find an authoritative source that says F into A is OK, and A into F is a problem, I would not risk it. I think I'd find someone with a '64 to '80 something Ford and give them the type F.

 

[doug7740]

I would not mix Dextron/Mercon with Type F transmission fluid, you are only asking for trouble. Once you figure out where the transmission fluid is leaking from, let us know so we can advise you on how to repair the leak. I don't know where you are located, but in the Cleveland area Advanced Auto Parts keeps Type F transmission fluid in stock.

Attached is an article on automatic transmission fluid. I hope this will help you decide what kind of transmission fluid you should use in your 1957 Thunderbird.

doug7740
1955 Thunderbird Blue

 

[Mrujoint]

I would not mix Dextron/Mercon with Type F transmission fluid, you are only asking for trouble. Once you figure out where the transmission fluid is leaking from, let us know so we can advise you on how to repair the leak. I don't know where you are located, but in the Cleveland area Advanced Auto Parts keeps Type F transmission fluid in stock.

Attached is an article on automatic transmission fluid. I hope this will help you decide what kind of transmission fluid you should use in your 1957 Thunderbird.

doug7740
1955 Thunderbird Blue

Thanks for the article Doug! After reading it, it would appear that I'm doing the right thing by using Type F trans fluid in my '55 TBird Automatic, correct?

 

[doug7740]

Thanks for the article Doug! After reading it, it would appear that I'm doing the right thing by using Type F trans fluid in my '55 TBird Automatic, correct?

Absolutely, When I replaced the transmission fluid and filter on my 1955 Thunderbird I used Type F transmission fluid. As I said, Type F transmission fluid is not hard to find. At least where I live.

doug7740
1955 Thunderbird Blue

 

[TJShea]

I would not mix Dextron/Mercon with Type F transmission fluid, you are only asking for trouble. Once you figure out where the transmission fluid is leaking from, let us know so we can advise you on how to repair the leak. I don't know where you are located, but in the Cleveland area Advanced Auto Parts keeps Type F transmission fluid in stock.

Attached is an article on automatic transmission fluid. I hope this will help you decide what kind of transmission fluid you should use in your 1957 Thunderbird.

doug7740
1955 Thunderbird Blue

Thanks for the insight. It appears that all fluids are certainly not equal. I really had no idea as my other vintage cars were all manuals. I will go with what the mechanic said,and the consensus here. He is at a rather large restoration/repair place here in Las Vegas. I figure he should know what he's talking about, I try to get second opinions when I can and this forum seems excellent for that. Just didn't know if the fluids were compatible. Looks like they are not. I will have enough Type F for power steering until the next ice Age. As for the leak, I think I need to get to a lift to get a good level look......

 

[Hele]

Hi friends, what kind of power steering fluid for a '57 Bird, Type A or Type F ?
Thank you!
Helmut from Germany

 

[doug7740]

Type A fluid was outlawed in the early 1970s in the United States, because it relied on a sperm whale oil additive to act as a friction modifier. Type F fluid is the replacement fluid for type A.

doug7740
1955 Thunderbird Blue

 

[MRansom]

Hi friends, what kind of power steering fluid for a '57 Bird, Type A or Type F ?
Thank you!
Helmut from Germany
[/QUOTE

 

[MRansom]

my ps dip stick says “ATF, purchased F from NAPA, to add when low

 

[TJShea]

I have an update on the leaking transmission. I found that the previous owner had put in a fancy looking dipstick that was shorter than the original. I thought it was part of the "dress-up" kit, however, it was not. Unfortunately, when it showed low, it was actually over the stock fill line. Adding fluid overfilled it, and I was told the transmission was "burping the excess out." So weekly I was adding more fluid, the car kept throwing it up, and I then restuffed it as I would have up to almost a 1/2 pint in a drip pan and the dipstick showed "low."

After reading things on this forum (this is a great info source for someone with my skill level) I bought two dipsticks from two different TBird parts suppliers. They were both the same length, and about 3 3/4 inches longer than the aftermarket fancy chrome one that was in the car. The "low" line on the fancy chrome one is just about at the "full" mark on the replacement ones I bought. The "full" mark on the chrome one was considerably above the full line on the replacement ones. Now, I keep the level mid way on the replacement one, and have had barely any leaking at all. The small amount leaked over 2 weeks is about the size of a quarter, if that. Car is running fine, seems to shift just fine, etc. I continue to use the DEX/MERC and all seems well. Thanks to you all for all of the info. And if anyone wants a fancy short chrome dipstick, I know where one can be had for cheap. Although it did suffer a rather substantial bend, kinda resembling a knot, 🙄

 

[Pink T-Bird]

Type A fluid was outlawed in the early 1970s in the United States, because it relied on a sperm whale oil additive to act as a friction modifier. Type F fluid is the replacement fluid for type A.

doug7740
1955 Thunderbird Blue

Doug, with all due respect you are mistaken. Type A is still used in some forklift and industrial transmissions. No whales involved. There once WAS a Case and John Deere tractor gear and hydraulic oil (JD-303?)that was used heavily in agriculture and construction equipment that used sperm whale oil as a major constituent. That went away in the 70s when the Endangered Species Act passed. I suspect someone misconstrued the two fluids when they informed you. https://www.nu-tierbrands.com/wp-content/uploads/2020/01/did_you_know_john_deere_303_thf.pdf

Here is the SDS safety sheet from the outfit I believe I last purchased two 2 gallon containers of Type A from about 5 years ago. https://www.warrenoil.com/MSDS-Spec/SDS/Warren/WOC021 - SDS - Warren Type A ATF.pdf

I was not suitably impressed by the slight difference in performance in my Edsel's cast iron cruise- o- matic compared to Dextron so have not sought it out recently.

 

[jimntempe]

Doug, with all due respect you are mistaken. Type A is still used in some forklift and industrial transmissions. No whales involved. There once WAS a Case and John Deere tractor gear and hydraulic oil (JD-303?)that was used heavily in agriculture and construction equipment that used sperm whale oil as a major constituent. That went away in the 70s when the Endangered Species Act passed. I suspect someone misconstrued the two fluids when they informed you. https://www.nu-tierbrands.com/wp-content/uploads/2020/01/did_you_know_john_deere_303_thf.pdf

Here is the SDS safety sheet from the outfit I believe I last purchased two 2 gallon containers of Type A from about 5 years ago. https://www.warrenoil.com/MSDS-Spec/SDS/Warren/WOC021 - SDS - Warren Type A ATF.pdf

I was not suitably impressed by the slight difference in performance in my Edsel's cast iron cruise- o- matic compared to Dextron so have not sought it out recently.

Whale oil was used in many hydraulic fluids. It was an additive, not the entirety of the fluid. It was a great corrosion inhibitor. Unlike oil, which drains off metal when it sits for a few days, the whale oil additive did not drain off. When whale oil was outlawed they continued to make Type A. The difference between with whale oil and without is where the "suffix A" comes from. The new formulation of Type A was called Type A Suffix A.. It had some other anti-corrosion additive to make up for the discontinued use of whale oil.

 

[doug7740]

Doug, with all due respect you are mistaken. Type A is still used in some forklift and industrial transmissions. No whales involved. There once WAS a Case and John Deere tractor gear and hydraulic oil (JD-303?)that was used heavily in agriculture and construction equipment that used sperm whale oil as a major constituent. That went away in the 70s when the Endangered Species Act passed. I suspect someone misconstrued the two fluids when they informed you.

Pink T-Bird,

Since I have never worked on a fork lift or a tractor I had no idea that they used Type A transmission fluid. Thank you for enlightening me. You learn something new everyday.

I am aware that Type A transmission fluid doesn't contain any sperm whale oil. When Type A evolved into Type A Suffix A and then into Dexron, each of these relied on a sperm whale oil additive to act as a friction modifier, at least until the use of whale oil was outlawed in the early 1970s.

doug7740
1955 Thunderbird Blue

 

[55blacktie]

In my estimation, the first thing to do, is to find out WHY the trans is low on fluid. Once you have that figured out, I've been told it's not really a good idea to mix transmission fluids. Kinda like oil, you're not supposed to mix synthetic and mineral, and so on. Might consider asking a local trans shop expert their opinion too. Best of luck with you "new to you" 57!

Ever hear of "synthetic-blend" motor oil? It consists of a "blend" of synthetic and mineral oil. Lots of shops use it because it provides better protection than pure mineral oil, but costs less than full synthetic. Some customers don't want to pay a premium for a full-synthetic oil change.

Mixing Dexron and Type F? There's lots of information available online. The consensus is "yes," they can be mixed. However, Type F has no friction modifiers and won't offer the same protection/life as Dexron. Type F is fine, if you want to change it more often. Also, if your transmission has ever been rebuilt, the four fiber plates in the clutch pack probably aren't made of the same material that was used in 1955-1957.

 

[jimntempe]

Whale oil was used in many hydraulic fluids. It was an additive, not the entirety of the fluid. It was a great corrosion inhibitor. Unlike oil, which drains off metal when it sits for a few days, the whale oil additive did not drain off. When whale oil was outlawed they continued to make Type A. The difference between with whale oil and without is where the "suffix A" comes from. The new formulation of Type A was called Type A Suffix A.. It had some other anti-corrosion additive to make up for the discontinued use of whale oil.

Correction, it was not the shift from A to A Suffix A that was the whale oil switchover.. when Whale oil was outlawed the result was Dexron II (C spec) was updated to Dexron II (D spec).

 

[doug7740]

So everyone understands the evolution of automatic transmission fluid, the article below should clear things up. Keep in mind that this is an older article and that automatic transmission fluid has evolved even further since it was written.

doug7740
1955 Thunderbird Blue

 

[Denis1957]

I had some work done on my new to me 57 a couple months ago, which included work that required the automatic transmission to be drained. . I am pretty new to owning a 57 T-Bird, and having a 50's era automatic transmission, so I am a novice on some related things . The repair tech said that "transmission had been worked on" so Dex/Merc transmission fluid would be appropriate, and that is what they used. Previously, I had bought a couple of containers of type F transmission fluid to have on hand. Today, I noticed the transmission to be a little low. Can I add/mix type F with Dex/Merc, or am I just asking to problems in the future. Hate to just waste the Type F, but I surely Ii not want to screw up the transmission over a couple of containers of fluid.

I have been told the 2 fluid types are not compatible.

 

[Tom Alpers]

They are "compatible" in the sense that they are pretty much the same oil and can be mixed. The primary difference is that F has no friction modifiers whereas Dex has friction modifiers. As a result, the Dex doesn't "grab" and shifts smoother. If you use F it may increase shift harshness/firmness. Some people want that. If you have been happy with how your transmission has been operating, you should only put Dex/Merc up to the "III" version in it or any ATF which says it's compatible with Dex III. If you put F in it could change how it shifts. If you don't like the change you will have to do a complete drain and refill to get back to where it was. Save the F you have and use it in the Power Steering, if you have PS.