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i have also seen this happen with trannies. what i believe is the problem is, it is not the new fluid being bad, but the people that change the fluid also adjust the bands at the same time, and i believe that alot of them adjust the bands wrong. not saying this is the problem in all cases, but maybe some of the cases. just my $0.02 on that subject.

on the subject of using type f fluid in your tranny, i would advise against it. type f has a different coefficient of friction, and viscosity than dexron or mercon. i am not sure if it is heavier or lighter. if it is heavier it would probably be about like using 80w90 in your engine, and if it is lighter it would probably be like using straight 10 weight oil in your engine. either way not a good thing. another example would be using regular gl5 fluid in a limited slip rearend.

the type f fluid probably wouldn't hurt your tranny right away. however, i am sure it would increase the wear on your tranny and make you have to do a rebuild alot sooner than using the fluid that was designed for your tranny. also, just my $0.02


eric
 

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our auto diesel teacher had always said never add f to GM/mopar trannies or vise versa. with adding the f you get harder shift but he said it is taking out your clutch plcks. other way GM fluid in ford you cause so much slippage that they re buned out pretty quick. he could be wrong. just voicing his opinion for him.
 

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Cbody said:
Personal theory is that you develop a buildup of scum internally (rather similar to "glazing"), and the fresh atf acts as a more harsh detergent than the old, and starts cleaning the internals, which then get lodged in the pistons, and cause slight sticking..........nothing noticible, but enough to slightly reduce pressure/volume to the point that the clutches don't quite grab like they should........which leads to increased heat, and that's what actually causes the problems. The heat breaks down the atf quickly, and the clutch slippage creates more debris, both of which in turn conspire to turn the situation into a catch-22.
Very sound reasoning. And I'm inclined to agree. As most of the transmission troubles I've seen were in the valve body. Usually due to improper maintenance. Never cleaning the valve body's internals, which is directly responsible for the tranny's shifting operations.

Type F. If this is for a later OD, then no I wouldn't use it.....I'll wait 'till some other sucker tries that out and gets enough miles under their belt to determine how well it works or how detrimental. The OD's seem to respond poorly to anything but the oddball later fluid (7176 or something like that), and they're built "on the fringe" enough (strength wise) that I'm loathe to test any other fluid in them. Perhaps someone here can chime in with real-world results on the OD's and type F, but they're too $$ for me to run trials on............especially since nearly all the OD's I've worked on are customers vehicles. Hopefully txs will respond to this thread, if not someone ought to IM him, he may have insight that I'm ignorant of.
"Built on the fringe". Funny you should say that Jay. My buddy who is an insurance adjuster by day, and a Mopar junky by night, adjusted an insurance claim for a Chrysler drivetrain engineer. And this guy told him straight up that the new auto transmissions were garbage. I don't know personally, because I've never worked on them. But it sure wouldn't surprise me.

If it's the older regular 727/904 then hell yes run it, it sure won't decrease the longevity, and in fact should increase it due to quicker clutch engagement (less heat, less clutch material removed, etc.) The faster a transmission shifts the better off you'll be (not "harder", *faster*), since there's no drawbacks associated with quicker clutch pack/band engagement that I'm aware of (excluding NVH in passenger cars), and type F will help in that department.
Jay
Words of wisdom. I've used straight Type F in all my 727s for at least the last 15 years. With no problems whatsoever. They shift better with Type F than the Dexron stuff. And a quicker shift is just as Jay stated. Better for the clutch packs, as heat & slippage is what breaks down the frictional material of the cluthes & bands.

And if there was a problem with running Type F in 727s, I figure it would have surfaced long ago. As I've used nothing but Type F....................Los
 

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Glad u brougth this up Mohammad will definitely go the Type F route with this tranny .

bt83rc

PS: Jay and Calos u 2 still kick ass !!!
 

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A day late and a dollar short again. LOL I'm just going to agree with the thoughts of this thread. In the OD tranny, use only the recommended. 7176 (or what ever its called) is the Chrysler designation. In the normal world its called ATF +3. They've since begun requiring ATF +4 in the newest stuff, and recommending it in place of the +3 stuff. I personally think the wrong fluid in the OD autos (and lack of maintainance) is a major contributor to the problems of these trannies. The wrong fluid probably all a "fringe" design needs to push it over the edge. www.allpar.com has some interesting reading on the subject.

I've heard the Type F advice so many times for the 727, that I bought a case of Type F to try out in my RC. Hearing Jay, Los and Mohammad all recommend Type F in the 727 has given my the gusto to charge blindly into my Type F conversion. 8)
 

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tv_larsen said:
A day late and a dollar short again. LOL I'm just going to agree with the thoughts of this thread. In the OD tranny, use only the recommended. 7176 (or what ever its called) is the Chrysler designation. In the normal world its called ATF +3. They've since begun requiring ATF +4 in the newest stuff, and recommending it in place of the +3 stuff. I personally think the wrong fluid in the OD autos (and lack of maintainance) is a major contributor to the problems of these trannies. The wrong fluid probably all a "fringe" design needs to push it over the edge. www.allpar.com has some interesting reading on the subject.

I've heard the Type F advice so many times for the 727, that I bought a case of Type F to try out in my RC. Hearing Jay, Los and Mohammad all recommend Type F in the 727 has given my the gusto to charge blindly into my Type F conversion. 8)
When you guys are referring to the OD trannies, do you mean the A518, or the newer ODs (don't know the designation, and don't care 8) )? I was understanding that a 518 is basically a 727 plus an OD module grafted on. Or am I disillusional? :-\
 

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I just asked Dean Mosely w/Mose's Transmissions this question a few months ago. Dean has built 6 transmissions for me & their shop has been in business since 1956. Dean confirmed Jay's "scum" theory and said if you change your fluid every 30k or so like most manufacturers recommend, you won't have this problem, but if you rack up the miles first it is more likely to occur.

I only use Mobile 1 synthetic transmission fluid, gear oil & 15-50w in the engine. Besides the info provided by Southwest Research, I've had a 1990 Maxima go 266k miles w/o burning oil & no work to tranny and my 77 RC had 277k miles before needing the current rebuild (bought w/80k already on the odo).

Brad
 

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On the newer overdrives I would stick with the 7176, on my old truck 727s I run a witches brew of type f and transdraulic which is used in large tractor rearends. transdraulic fluid is a hair thicker viscousity, three quarts of type f thins it out some, it still has to warm up a little to shift when it is very cold out (like 0) The only reason I would agree with the opinion that the newer trannies are junk is all the frikkin electronics, most of the hard parts beside the O/D pieces the average person couldn't tell the difference between new and stuff made in 1962. And then there are little things like some idiot deciding to use plastic cooler fittings, there's a smart cookie. At least chrysler has avoided the temptation to use the variable displacment pumps that gm uses, there's a real piece of shit for you.
I think all the selenoids does something to the fluid over time, I know in the lock-up 404s changing the fluid almost invariably will cause the govenor weights to hang up.
 

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Cbody said:
518, 46RH & RE, are all basically the same OD, and are all essentially 727's minus the compounder. The "newer" OD's are really still 727's with only minor revisions regardless of how you look at them. In fact you'll find that the nomenclature overlaps, meaning that say a '96 46RH can still be called/known as a 518.
Jay
So why are they considered a "fringe" or marginal design? Is the basic tranny still stout, and it's the compounder that is the problem? Reason I ask, I'm planning to go to one in the Ramus before long, and I don't want it to be weak.
 

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I've heard pretty much the same thing that Jay had to say about the scum theory. The same reason i refused to do a transmission flush when i worked on cars for a living. I've heard that type F and dextron III aren't very compatable. But also heard like many of you say, to use it for the exact reasons you all mentioned about quicker shifts. I worked in a tranny shop for a short little while and they put dextron III in everything. didn't matter if it was a ford that required mercon v or a mopar that required +3. Well guess what, they had alot of mopars that came back with tranny problems and half the work they did was mopars. So everyone there just hated Dodge and said they had shitty transmissions. And it was all in just being the wrong fluid used. Up till about 95 the 518 doesn't really use that much more electronics, only for the lock up torque converter. everything else is still hydralic. What kills these transmissions is heat build up with having a OD unit on it and some seal that starts leaking. The main thing is on the newer Dodge trucks is to make sure you have the biggest tranny cooler you can find on it.
 

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The scum theory makes sense. I have also heard people say that with a tranny that has higher miles and never had the fluid changed, that the internals are worn, but that since there is alot of tiny pieces of metal floating around in there (that are small enough to go through the filter), that they act as a friction modifier. Similar to LSD additive being added to a rearend, this material keeps the tranny from slipping. And when flushed or drained and replaced with fresh stuff, allows the tranny to start slipping.

On my personal vehicles that have been properly maintained, I have the tranny flushed every 30,000 miles and have had autos go forever with no problems.
 

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well, here is my 2 cents worth. On the type F. USE IT! I've run nothing but type F in all my older Mopars for years. Including my drag cars that I have owned.I have never had a fluid related problem. Buy the biggest cooler you can mount in the truck.
When I did my stint at the dealership, I replaced quite a few 518's and the fluid was cooked in them all. 9 out of 10 didn't have an external cooler.
My experience with type F in a 518 has been very good. After replacing the trans in my dakota with a fresh unit I began to have trouble with the fluid staying cool. I added an add on cooler and even bypassed the rad cooler and ran it straight in and out. The fluid was still getting warm. I thought what the heck and put in type F(hell it was under warranty anyway) Over 60k later and still trouble free. There is no lag or slip and the shifts are very crisp.The fluid is changed every 30k and there does not seem to be any breakdown of the fluid. In short, I'm very happy with it.

Do I recommend someone else trying it? Hell No! this has worked great for me, but I'm not going to tell someone else to try it. This is on an early model(1992) 518.
On the later ones, use Mopar 7176 accept no substitutes(Dexron is a no no) I have had good luck with the Penzoil ATF+3.(7176 replacement) for Chryslers only.
I understand that mopar has come out with another updated fluid but can't comment on it.

as far as changing fluid in one that has never been serviced-then having the trans go away-YEP! Had it happen to me twice.
 
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