Chrysler Automatic Transmission Fluid

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Aug 15, 2002
Southern California
This forum is unbelievable, Had no Idea that there were this many "Lubricant Junkies" out there. I bought a 1998 Jeep Grand Cherokee last year and noticed that it requires a product called ATF+3 for the tranny. The new ones use ATF+4. I know that the Amsoil synthetic ATF satisfies all the requirements of the Chrysler trannys as well as all the other cars that use Dexron. It would seem to me that this would be impossible as the "grabiness" of the fluid is either there or it isn't. I am curious as to what the experts out there have to say about this. Ed
Ed, Back in the days where there were primarily 2 types of fluid, the Amsoil "might" have worked. My understanding is Chrysler products of the last 12 years are very weak when it comes to drivetrains. The engineers tried to "fix" the problems by updating the fluid types and friction characteristics. If it were my vehicle, I'd stick with what the manufacturer states (or upgraded version), rather than some "Universal" fluid that may or may not work. Hapuna
I agree but the folks at the Jeeps Unlimited forum talk about Amsoil ATF as if it were the liquid from the gods. It would seem to me that if ATF+3 could make a weak transmission give acceptable performance wouldn't it make sense to use it in a transmission where dexron is specified.?
To meet these certian ATF requirements the fluid must be tested IAW the standard set forth for that particular specification. Amsoil has formulated thier ATF, to meet the specifications of ATF+ through ATF+4, also to meet Dextron and Mercon through Mercon V. I have some customers with dodge trucks and they are going 60,000+ mile drains in their Transmissions. I would guess if there were a problem it would have surfaced by now. Also not, that the ATF specification is designed for a manufacturer to meet the bare minimum, Amsoil over-engineers their fluids to well exceed most if not all standards.
The recommended torque curves for maximum durability on GM transmissions (Dexron) and Ford Transmissions (Mercon) are the same. The differences in their minimum standards lie in areas where it is easy for one fluid to cover both. The Chrysler transmissions are diffferent. You can see the graph of the torque curves one my site under "aplicaciones". You cannot have one fluid that correctly covers both. Dexron in a Chrysler transmission will cause more abrupt changes and additional wear. ATF+3 in a Dexron-designed transmission will cause slippage and wear on shifts. Their are additives that claim to change the friction characteristics, but they don't work either, as demonstrated on that graph. Fluid characteristics for Type F are much more abrupt and damaging to both. ATF+3 or ATF+4 should be in those transmissions. ATF+4 is supposed to be backwards compatable, but I believe that for now it is sold only by Mopar. I think it is a group III fluid, but I have not been able to confirm that. I believe the differences in performance between +3 and +4 are only in their resistance to oxidation and longer life, maintaining the same torque curves, but Chrysler wont't say. If I can ever find out I will post is as well.
Ed, Amsoil made an special purpose ATF +4, synthetic transmission fluid for about a year, along with their Dexron/Mercon product, so they are certainly capable of doing so. This product disappeared when they came out with their dual use synthetic ATF. I have a number of customers who run this fluid in Chryslers, including Dodge diesel pickups that pull heavy loads. I have heard no complaints about it. I run it in an application that calls for Dexron II (an older Audi) and it works fine there as well. I suspect the amount of friction modification in this fluid is somewhere between the Dexron and ATF+4 specifications. TooSlick
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