mixing transmission fluid types

[lil red]

hey guys

had the motor and trans out the truck, did a little work to the trans, put it all back together and added fluid

The local dodge dealership told me to use ATF+4 and thats what I used to fill it back up to full - it used about 4 litres to do so

I went back to Napa to get 1 more litre and all they had was ATF+3 and was told the only difference was additives - and ATF 2,3&4 were compatable. I recently read that ATF+4 is synthetic? Is this true?

I don't know exactly what was in it for the last umpteen years - but I would have bought the fluid from chrysler.

anyway- im now doubting what I did - would it hurt to mix them?

(it's a 1979 727 loadflight behind an summertime street driven 325 horse 360)

 

[1970Duster]

ATF+4 is full syn. The others 2,3 are not, so do not mix them.

 

[lil red]

ATF+4 is full syn. The others 2,3 are not, so do not mix them.

not that i doubt yourayer:

mopar says atf+4 is "backwards compatable" thats why i question mixability

 

[sr71mopar]

One quart won't hurt anything.

 

[lil red]

thanks man

 

[805moparkid]

they have +4 in syn and non syn

 

[lil red]

they have +4 in syn and non syn

ooh...that i did not know....i bought quaker state +4

 

[BillGrissom]

A long-running question. I decided to use ATF+4 in my old Mopars since I learned it is fully synthetic. The Autozone brand seems as good as the others when I read the back. Currently, I have Type F in my Newport's 727. I read that "F" means "friction", i.e. more friction modifiers than Dexron. It is also used in many Fords, so people say that explains the F. Since then I read that ATF+4 has even more friction modifiers than Type F, so it seems better overall. I recall Mopar info suggesting Dexron best for older trannys, but that might have been before ATF. More friction is good if you want your clutch plates to last (fast, firm shifts).

Where it really mattered was the first Mopar electronically controlled trannys (A604, etc) in most V-6 minivans. ATF was rare then so some Mopar marketing genius had the owner's manual state that one could use Dexron when ATF wasn't available. Tranny shops took that to mean they could use cheaper Dexron at will. Many transmissions failed from that little comment. They would "shudder" and burn up the clutch plates with the slippery Dexron (plus controller instability?). A big black mark for Chrysler.

 

[Abodybomber]

Fwiw,I used to sell auto parts.As far as I have seen,all the house brand label lubricants are all manufactured by Ashland.(Valvoline)

 

[lil red]

thanks bill- thats the info i wanted

 

[magnumdart]

I never had any trouble with type F in any car. But putting Dexron in a Ford could result in disaster. I think type F Was formulated for C-4 and C-6 trannys because they opperate at a higher temp than 727's, and turbo-hydromatics. I never mix synthetic and non synthetic gear lubes together in heavier equiptment and probably only do it in my car in an emergency type situation.

 

[cudamark]

An older model 727 like yours will take just about anything and be happy. I buy whatever is the best deal at the time. Anything on the shelf these days is better than what was available back when that transmission was designed.