pist5.0 said:
I had dexron in my 01 and after about 8 months started to have a whine from the bellhousing. It sounded like a power steering pump going bad, but it was faint. it varied with RPM as well. Over the next 4 months the noise got worse to the point everyone noticed it. I figured i was losing a pump, but it shifted fine and no leaks. I figured it couldn't hurt to put ATF 4 in it since it was recommended. The noise went away after a week. Now it could have been because it was Valvoline Maxlife Dexron/Mercon3, not sure, but no probelms what so ever now. The Mopar Dexron should be ok. According to Alldata ATF4 is recommended. I used full synthetic. I think if you go with the service manual advice you should be ok.
According to the FSM, GL-5 gear oil is just fine in the AX-series transmissions - but it don't work. Experience has shown that the bronze synchroniser rings in the transmission get attacked by the sulphur added to GL-5 gear oil (not just the AX-series gearboxes, either. I've known some of the old Muncie SM-series and the old Ford Toploaders to have the synchros dissolve as well.) And, GL-5 is recommended by both the FSM and the owner's manual.
They're wrong. GL-3 is preferred, and GL-4 is acceptable - but GL-5
will damage your transmission with significant use. Anyone else that recommends GL-5 for transmissions with bronze internals is also wrong - chemistry has proven that over and over again - as well as reports from the field and personal experience.
As I've been able to determine thus far, the friction modifier package in the ATF +series and the Dexron II/IIE/III fluids are different (I don't know about Dexron VI yet.) That's what causes the chatter and such. Reports from the field are consistently bad on using ATF +3/+4 in the AW4, and there are reports from the field that show that the use of synthetic DII/IIE/III cause similar problems (because the synthetic fluid actually lubricates
too well.)
Also, there is a "DII" stamped into the drain plug itself - meaning that the Aisin factory endorses the use of Dexron II fluid. Dexron IIE and III are reverse-compatible with Dexron II (again, I'm not sure about Dexron VI. I can still find DII/IIE/III without too much trouble, so I've not been inclined to investigate.)
"MOPAR Dexron" may be a misnomer - since the MOPAR fluids are all supposed to be ATF +3/+4 now (they haven't used Dexron/Mercon in years, but it's the old GM and MOPAR spec. "Type F" was the old Fords, and most Japanese automakers used Dexron for a number of years. I haven't seen Type F in quantity in a while, but it does make a good hand cleaner in a pinch. Use that stuff in early C3/C4/C6, Ford-O-Matic, FMX, and the like.)
As far as "companies with entire departments to check those things," I don't doubt what you're saying - but also bear in mind the effect that accountancy has on things like that. Granted, processes have improved - but a good example is that the connecting rods in the third-gen HEMI aren't forged. They're made from powdered metal and the bit ends are 'cracked' to separate the cap. Why? Because power metallurgy is cheaper than forging.
As I've said, powder metallurgy processes have improved significantly. However, another example of powder metallurgy is the little knuckle on early XJs (up to 1995 or so, I think) that the bottom stud of the power steering pump rides in, and that rides on the long 5/16" screw to adjust the belt. I've broken four of them so far - they all snapped on the end with the threaded hole. Oops. It was probably a bit cheaper to make that part using powder metallurgy - but I'm willing to bet that the engineer who designed that originally specified wrought stock machined to size. Hell,
cast parts would be better there, given the processes available at the time!
So, I could see that the accountants would simplify things down to ATF +3/+4 companywide, and figure that the simplified logistical train would more than offset the "occasional" warranty service from non-Chrysler transmissions. Then they convinced the legal department that it would work out. Meanwhile, the engineering department was probably swearing at accounting and legal the whole time.
"I am the engineer, you are the beancounter. Your job is to keep track of my beans, not tell me what to do with them!" - Mickey Thompson, ca. 1985.
