DEXRON ATF VS POWER STEERING FLUID

[CFD244]

Hi Folks

Back in the day, we used Dexron ATF in the power steering systems in our old Mopars because it was readily available. We never had any issues with the combo whatsoever. But as I am putting on the finishing touches of my '71 Demon, I see in the service manual and owners manual that it specifies power steering fluid and advises "Caution" DO NOT to use transmission fluid........So what gives?

I was speaking to an fellow that has been building Mopar boxes for 50 years. When he finishes, he tests them with transmission fluid. He told me that he has been using Dexron in his PS systems for years.......He is a Mopar guy.

So if you buy one of his rebuilds, what do you do? Use ATF, or just top up the system with PS fluid? Does it matter? I assume that the 2 could mix if there was a little trans fluid left in the box after testing?

So what is the consensus?

Thanks
FABO

 

[RustyRatRod]

Dexron was never ment to be a substitute for P/S fluid. I don't know how or why that ever came to be. If you're going to us something besides P/S fluid, and are just dying to use ATF, use Ford Type F. It's hydraulic fluid and that's what P/S pumps use.

 

[CFD244]

Dexron was never ment to be a substitute for P/S fluid. I don't know how or why that ever came to be. If you're going to us something besides P/S fluid, and are just dying to use ATF, use Ford Type F. It's hydraulic fluid and that's what P/S pumps use.

My concern was more about the little bit of Dexron that may be left in the box after testing. I use PS fluid......Will a little bit of Dexron mixed hurt anything?

 

[RustyRatRod]

My concern was more about the little bit of Dexron that may be left in the box after testing. I use PS fluid......Will a little bit of Dexron mixed hurt anything?

Probably not.

 

[4mulas]

Why not just use power steering fluid. Another good reason to use it is if you have leaks you can discern if it’s transmission or power steering. Pwr steering is clear.

 

[413]

Don't use ATF in power steering if you care about the car. It better than going dry though. I bet ATF of today is different than the good old days ATF.

Put the return line in a catch can and crank over the engine and flush out the residual ATF. Don't start engine, then it will blast fluid everywhere.

I like Napa power steering fluid, it is almost clear when new. Do not use the PS fluid with stop leak, especially in a newer box.

 

[oldkimmer]

I’ve never used anything but Dex in a Mopar for over 50 years. All other PS fluid. Kim

 

[Bewy]

According to Lee Manufacturing, p/s fluid has more 'lubricity' than ATF & only p/s fluid should be used for p/s units.

 

[CFD244]

I’ve never used anything but Dex in a Mopar for over 50 years. All other PS fluid. Kim

That's all we did in the 70's and 80's as well. Never a problem......Hell, my old truck even specs Dex.

I will flush the box and do PS fluid in this one.

 

[LO23M8B]

I've used Dexron in my vehicles and customer cars from the 60's till today. Never an issue. But if you.re concerned about it just use the ps fluid. As far as being a hydraulic fluid what do you think a trans. is? My Mohawk Lift even recommends Dexron.

 

[oldkimmer]

Dexron was never ment to be a substitute for P/S fluid. I don't know how or why that ever came to be. If you're going to us something besides P/S fluid, and are just dying to use ATF, use Ford Type F. It's hydraulic fluid and that's what P/S pumps use.

Is a tranny not a hydraulic pump?

 

[Ceedawg]

Today there’s different grades (mixtures) of Dextron. I think the Dex of old is no longer availible. Back in 94 I used it in my 92 diesel truck trans, overheated and slipped. Read in the 92 SM to NOT use it, use the factory fluid so changed it out and trans worked great after that!

 

[Charrlie_S]

!964 Ply service manual specs PS fluid.

 

[CFD244]

I flushed the box with clean PS fluid, then refilled the system with new PS fluid.

Thanks for everyone's input.

 

[Bewy]

Yes, a tranny has a hyd pump. It also has clutches & bands, which p/s boxes do not have.

 

[JDMopar]

Off topic....but,

One thing I can tell you NOT to use Dexron in, is any older FWD Mopar car with an A604 transaxle. Way back when, my wife had a 96 Chrysler Cirrus. Transmission line got a slow leak, so I threw some Dexron2 in it not knowing any better. Seals inside of it swelled up and threw it into limp mode due to not using ATF+4, so it had to come out and be rebuilt. Probably not many of those old junk pile FWD cars left around....but just a heads up.

 

[Ceedawg]

Off topic....but,

One thing I can tell you NOT to use Dexron in, is any older FWD Mopar car with an A604 transaxle. Way back when, my wife had a 96 Chrysler Cirrus. Transmission line got a slow leak, so I threw some Dexron2 in it not knowing any better. Seals inside of it swelled up and threw it into limp mode due to not using ATF+4, so it had to come out and be rebuilt. Probably not many of those old junk pile FWD cars left around....but just a heads up.

Like I said on mine, it’s Dextron but not compatible with and trans. I don’t know if any Dextron is made for a Mopar today. Not like back in the day. A lot of racers are using John Deere hyd fluid now (comes in thick or thin)

 

[Johnny Dart]

That's all we did in the 70's and 80's as well. Never a problem......Hell, my old truck even specs Dex.

I will flush the box and do PS fluid in this one.

So if that's what you did, why stop now ?

 

[CFD244]

So if that's what you did, why stop now ?

LOL......'Cause you fargers got into my head.

 

[Swinger 340]

Dexron was never ment to be a substitute for P/S fluid. I don't know how or why that ever came to be. If you're going to us something besides P/S fluid, and are just dying to use ATF, use Ford Type F. It's hydraulic fluid and that's what P/S pumps use.

I also use Type F in my transmission for years, with no issues.

 

[Woody500]

Type F has more friction enhancers, but not as much as plus4, is what I've understood.

 

[TrailBeast]

Type F in the trans and steering both in every older car I have ever owned for my entire life with zero issues.
(And that’s been a while)

 

[LO23M8B]

Off topic....but,

One thing I can tell you NOT to use Dexron in, is any older FWD Mopar car with an A604 transaxle. Way back when, my wife had a 96 Chrysler Cirrus. Transmission line got a slow leak, so I threw some Dexron2 in it not knowing any better. Seals inside of it swelled up and threw it into limp mode due to not using ATF+4, so it had to come out and be rebuilt. Probably not many of those old junk pile FWD cars left around....but just a heads up.

We were talking about the p.s. I always use what the mfg. recommends for the trans. with my exceptions for my hot rods.

 

[dadsbee]

Must be time to go fishing soon....

 

[413]

DEXRON does not have a T

Sport Fury, not Sports Fury