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#34233 - 02/03/07 06:31 PM ATF 4 versus Dextron III whats the difference?
mopowergtx Offline
master

Registered: 06/18/06
Posts: 3048
Loc: Eastern Ohio
Whats the difference between ATF 4 and Dextron III that my 2001 Ram and my dads 2004 Ram both call for ATF 4 in the owners manuals? Why cant you just use the Dextron III the same as Ive been putting in my 904 and 727's for years?

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#34234 - 02/03/07 06:51 PM Re: ATF 4 versus Dextron III whats the difference? [Re: mopowergtx]
Anonymous
Unregistered


ALL I KNOW is that when you use the atf+4 or atf+3, your tranny looks like brand new, when dropping the pan, clutches are like new. dexron III is like old technology, good but not great

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#34235 - 02/03/07 06:53 PM Re: ATF 4 versus Dextron III whats the difference? [Re: mopowergtx]
Anonymous
Unregistered


Dont know exactly but most mopars for some time now have required atf+3 or atf+4 in both cases you can use valvoline maxlife atf in place and its much cheaper

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#34236 - 02/03/07 06:55 PM Re: ATF 4 versus Dextron III whats the difference? [Re: mopowergtx]
Locomotion Offline
master

Registered: 01/19/03
Posts: 5163
Loc: Florida
I'm no engineer or chemist, so I can't detail out the reasons. But it does have to do with application, clutch material, fluid pressures, valve body programming, etc. You can also throw in Type F and Mercon transmission fluids also. I try to stick with manufacturers recommendations unless there is ENOUGH proof that something else will work as good or better. One example is using conventional or synthetic Type F fluids in race torqueflites.

But from what I understand, the ATF 4 is a higher quality fluid than Dextron III and may be synthetic.

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#34237 - 02/03/07 07:09 PM Re: ATF 4 versus Dextron III whats the difference? [Re: Locomotion]
Anonymous
Unregistered


the info I shared is direct from valvoline

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#34238 - 02/03/07 07:40 PM Re: ATF 4 versus Dextron III whats the difference?
74chargr Offline
member

Registered: 12/21/05
Posts: 114
Loc: federal way, WA
I do believe atf4 is synthetics, which is used in all new chryslers. If of course is better for the tranny
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#34239 - 02/03/07 07:59 PM Re: ATF 4 versus Dextron III whats the difference? [Re: mopowergtx]
GO_Fish Offline
super gas

Registered: 07/18/03
Posts: 6161
Loc: Maryland
Old mopar transmissions were very flexible on ATF fluid type. Late model mopar transmissions are NOT. They are very sensitive on fluid type. Unless you want a smoked transmission and a very large repair bill, use exactly what is specified on the trans dipstick or a known exact equivilent. Fill the tranny with the wrong stuff and you will shortly be buying a new transmission.
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Scott B. "I'm a self-made man... I started with nothing, and I still have most of it!" 68 360 rusty B'cuda 'vert (GO Fish)13.59@ 98.72 mph 69 340 GTS stock 14.18@ 95.60 mph 01 5.9L Ram 1500 Quad Cab 4x4 01 3.5L 300M 16.23@ 86.97 mph

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#34240 - 02/03/07 08:23 PM Re: ATF 4 versus Dextron III whats the difference? [Re: mopowergtx]
Anonymous
Unregistered


ATF IV is a group III synthetic transmission fluid that Chrysler has developed and licensed. I believe it also has a friction modifier in addition to other additives. As far as I know, Valvoline is the only aftermarket manfacture of the ATF+IV.

I understand that you could use Dextron, but need to ad Lubeguard to make it work...I personally would stay away from this method.

I am using Redline ATF C+ spec for my new Chrysler transmissions...Redline is an Ester based group V ATF. On a side note: Redline is not licensed ATF+IV, but it is the best ATF in my opinion.

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#34241 - 02/03/07 08:32 PM Re: ATF 4 versus Dextron III whats the difference? [Re: GO_Fish]
Dave_J Offline
Big 50

Registered: 01/22/03
Posts: 2515
Loc: Auburn WA
What Go Fish said is true. While not a Ram, my 92 Plymouth Duster with the A-604 OD was due for a fluid change so I asked a few places to include the dealers parts man. All said Dexron III was ok to use. WRONG! WRONG! WRONG! $1500 later and I had a new trany. Go to Allpar.com and read some http://allpar.com/fix/trans.html befor you do a big boo boo. DaveJ
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SSG/E-6 Retired, US ARMY Posting cheap tech help (CRAP) here since Nov 97, 1000's of posts, most good. 03 Suzuki Burgman 650(Burger King) 08 Suzuki Burgman 650 Daily ride 41 miles one way 65 Formula S Cuda 78 Little Red Express Truck 98 Buick Century (wifes car)

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#34242 - 02/03/07 09:49 PM Re: ATF 4 versus Dextron III whats the difference? [Re: mopowergtx]
gregsrt Offline
top fuel

Registered: 01/14/07
Posts: 2423
Loc: SK,Canada
The difference is in the chemistry of the fluids,additives etc.Use whatever the dipstick says. If it says ATF+3 then use ATF+4 as Chrysler sent out a TSB to use it in place of the +3 last year. Besides if you have warranty and you use the wrong fluid, the dealership will not warranty it if they find out. Believe me I work in the service dept at a Dodge dealer.$2500++ to rebuild is a lot more than the correct fluid now.
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#34243 - 02/04/07 07:23 AM Re: ATF 4 versus Dextron III whats the difference? [Re: gregsrt]
shaker340 Offline
enthusiast

Registered: 08/06/04
Posts: 310
Loc: Eastern Ontario
Very interesting discussion, and I agree that one should never use anything but ATF+4 in the newer transmissions. But I have been using ATF+4 in my A-727 for about three years now and haven't noticed anything different than using a Dextron fluid. I have never used type F either so I can't comment. So does anyone have any info on using ATF+4 on older transmissions good or bad??

Mike
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#34244 - 02/04/07 07:32 AM Re: ATF 4 versus Dextron III whats the difference? [Re: shaker340]
Anonymous
Unregistered


I would also like opinions and experience using the newer ATF+ in older 727's instead of the dexron III. I currently run dexron III, is there a better product that will improve life and or performace of the trans? Thanks

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#34245 - 02/04/07 08:14 AM Re: ATF 4 versus Dextron III whats the difference?
GO_Fish Offline
super gas

Registered: 07/18/03
Posts: 6161
Loc: Maryland
Read the Allpar link. It says that newer ATF does not play well with old style trans seals and will cause leaks.

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#34246 - 02/04/07 09:32 AM Re: ATF 4 versus Dextron III whats the difference? [Re: GO_Fish]
moparx Offline
master

Registered: 09/03/03
Posts: 4935
Loc: north of coder
with all that has been said, i'll offer proof of my a604 in my 95 caravan. it has almost 300k on the clock. when i got it, the trans was a "chrysler" rebuild. it had 111k on it then. i have used dextron 3 in it, changing the fluid & filter every year. there are no leaks, it shifts fine[transgo kit added shortly after i got it], and the only problems i had was replacement of the input/output sensors a couple of years ago. my trans guy says the ATSG recommends dextron 3 for severe cold weather if shifting problems occure. i don't know. mine seems to be the only one i have heard about that still works good using this fluid. why ?

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#34247 - 02/04/07 10:17 AM Re: ATF 4 versus Dextron III whats the difference? [Re: GO_Fish]
JohnRR Offline
I Win

Registered: 01/20/03
Posts: 70955
Loc: U.S.S.A.
Quote:

Unless you want a smoked transmission and a very large repair bill, use exactly what is specified on the trans dipstick or a known exact equivilent. Fill the tranny with the wrong stuff and you will shortly be buying a new transmission.




sorry , i can't agree with this, i have a 2000 ram with a BOMBed Cummins and a 48RE , it has had nothing but dexron III in it since i starting turning up the HP , i changed out the +3 at about 39k and haven't looked back, truck has 189k on it.

i rebuilt the trans at about 89k , that was after i let someone else try out my new turbo , truck was puttting about 450HP to the rear wheels at the time , and i stupidly didn't go on the test drive . i drove it 40K miles with a slipping trans, if i did anything other than commute back and forth to work , and this was with dex 3 , only the front clutch pack was smoked .

i've got about 100k on it since the rebuild and its acting up a bit , but everything i see is pointing to the PCM or the TPS (going in and out of lockup as i can see the signal dropping out) , it's not the trans itself. the truck also has an overlap issue for the last 100k miles (i have 6 clutches in a 4 clutch drum with about .120 clearance and its not enough clearance ???), i use BW hi energy clutches and there is no signs of slipping with spirited driving on a non stock HP engine .

the +3 and +4 has additives partly because there is a surge issue with the lockup clutch , these fluids mask the issue, and also it helps the lockup clutch survive because chrysler has a poorly designed convertor, in diesels anyway and the RPM drop is about 400 rpm , the + fluid allows the lockup clutch to SLIP .


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#34248 - 02/04/07 11:03 AM Re: ATF 4 versus Dextron III whats the difference? [Re: GO_Fish]
GO_Fish Offline
super gas

Registered: 07/18/03
Posts: 6161
Loc: Maryland
Quote:

Read the Allpar link. It says that newer ATF does not play well with old style trans seals and will cause leaks.




I think everyone interested needs to read Dave's Allpar link and decide for yourselves. There always have and always will be those of us that like to roll the dice. Sometimes you win. And some of us here are smarter than the Mopar engineers... I am not. I have read enough about mopar trans failures in recent years that I'm not about to try and save $40 on ATF and then risk a $1500 rebuild. But that's just me!


Edited by GO_Fish (02/04/07 11:04 AM)

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#34249 - 02/04/07 01:33 PM Re: ATF 4 versus Dextron III whats the difference? [Re: GO_Fish]
Anonymous
Unregistered


ATF +4 is a synthetic transmission fluid. as such, it is more thermally stable than ATF+3 or others. as mentioned, there is a TSB chrysler issued stating that it is safe to supersede from +3, the only models it mentioned not to do such was 99 and older minivans, as they would not be able to break in a new torque converter clutch if replacement was required. i use ATF+4 on all my vehicles, expensive, but worth it.

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#34250 - 02/04/07 07:46 PM Re: ATF 4 versus Dextron III whats the difference?
Anonymous
Unregistered


I don't see a problem running synthetic atf in older Mopar transmissions. Been there done that.

https://www.amsoil.com/news/atf_new_specs.aspx

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#34251 - 02/04/07 10:10 PM Re: ATF 4 versus Dextron III whats the difference? [Re: GO_Fish]
JohnRR Offline
I Win

Registered: 01/20/03
Posts: 70955
Loc: U.S.S.A.
Quote:

I have read enough about mopar trans failures in recent years that I'm not about to try and save $40 on ATF and then risk a $1500 rebuild. But that's just me!




since i do my own rebuilds and it costs about 300 for a kit for a 47RE i'll take my chances .

the trans failures are CREATED by DCX , once pickups became the yuppie vehicle of choice the complaints started coming in about how harsh the trans ' engaged into gear , DCX's answer ? LOWER the line pressure , if they spent a little more time they could have taken out the harshness and not had issues with SMOKED trannys .

they finally did wake up on the 48RE and used many of the fixes the aftermarket did to get the trans to live behind a hi torque diesel motor .

edit .. oh and i'm not saying that dexII is the answer for all nor is + atf the antichrist , there is just alot of misinformation and SCARE TACTICS roaming around .


Edited by JohnRR (02/04/07 10:19 PM)

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#34252 - 02/05/07 09:21 AM Re: ATF 4 versus Dextron III whats the difference? [Re: JohnRR]
GO_Fish Offline
super gas

Registered: 07/18/03
Posts: 6161
Loc: Maryland
If you have the talent and time to rebuild your trans for $300, that puts you in a different camp than many of us. It would be a great hardship for me to even pull my trans out. (Side note: I blew up a 904 of mine after installing a simple shift kit in high school and have been intimidated by auto trans ever since.) My concerns about ATF type are greater for FWD trannys than for truck trannys... my perception is that the FWD is less tolerant.

My first post came across that incorrect fluid causes sudden and certain failure, and that does not happen every time as a couple of you have shown. To quote Dirty Harry "you've got to ask yourself punk, Do you feel Lucky??"

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