Hi Matt,
I respect your caution about upgrading to a full synthetic ATF. God knows these trannys are very sensitive to fluid requirements, and everyone who has ever put Dexron Mercon in by mistake, or believed some idiot at a trans repair shop who said it was OK to put it in, "as long as a friction modifier like Lube-guard is added", immediately had TC shudder and slippage. Such would require an immediate full system flush, a new MOPAR filter (not a close but no cigar knockoff), and a complete refill with MOPAR ATF +3. All true.
I know how you feel. The data. The data. Think about this though. How long were DCX's own TSB's on fluid (Trans OIL) for the A604 confusing and open to interpretation? I think their data is too often just profit driven bunkum.
All I can tell you is this. I have had great results with full synthetic ATF in my A604. I knew right off I had done the right thing because it performs far better.
It shifts way faster and firmer on WOT, like a properly installed shift kit would afford, and it shifts down perfectly too. Yet when driving "normal" with smooth light even acceleration, you can NOT feel it shift at all. I mean way waaaaay smoother than it did even when brand new. If the friction characteristics were not up to snuff, it wouldn't be able to do that, and you know it.
It runs much cooler now too, both in stop and go traffic in hot weather, and when taking a beating on the highway. If the friction characteristics were off, it would heat up, even if I really was too stupid to sense if was slipping, or the shift timing was off.
You know how these 4 speeds were designed to hang onto one gear while grabbing another, so they would have that "grocery getter smoothness", and how this means friction heat buildup. As you may know already. This is why a good shift kit can extend the life of these babies, IF DONE RIGHT. Yeah yeah yeah. I know. Most people can't install a shift kit right. Or they chose the wrong one and just wind up creating problems. But you know the idea behind getting one. Well now my A604 performs just as I told you above.
I believe that this full synthetic enables the A604 to actually perform as it was intended to by the designers. In other words. I think they are a great design, and really the old ATF +3 was just not up to the job. Not really. You had to baby them to get a decent life span out of them, by avoiding WOT and driving conservatively.
But for far too many people, over many years, [there is plenty of data on that!] driving conservatively and using only Mopar 7176 +3, Mopar filters and following their fluid & filter change schedule, did not get them the lifespan of the 3 speeds, and other car manufacturers transmissions.
Thousands of complaints over the years by A604 owners has given it bad reputation. But it wasn't the design. It was the ATF. The fact that DCX is pushing their new semi synthetic +4, only proves they knew it too. The A604/41Te4 design is a marvel! It was ahead of it's time, IF you used Mopar 7176 +3, but not if you were using one of the full synthetics.
Honestly Matt. Full synthetics like Redline C+ and Amsoil ATF have been around a lot longer than Mopar +4. Those who for years have been using these full synthetics in their's, with great results, have all along been denounced as liars trying to peddle snake oil though. It is a MYTH that only Mopar ATF should be used.
True, Mopar +4 is better than their old +3, but it is only a semi synthetic. It is a far less robust than a 100% full synthetic. I use it in my A604, for the same reasons that I use Mobil 1 in my engine.
I swear to you I don't sell the stuff Matt. In fact if I were you, I would go with the Redline C+, because they have a better reputation, and lots of race teams wont use anything else. I only have experience with Amsoil ATF though, and I do know from experience that it is great stuff. So personally I would buy Amsoil again.
I trust Valvoline pretty much. I mean they do have a reputation to uphold, and there are liability issues, but they say they have a +4. I don't know if it is just a copy of Mopar's semi synthetic +4 or not though. I suggest you try one of the full synthetics.
Or you can believe the myths. Like if you disconnect the air box on a Chrysler/MMC 3.0 and use a CAI instead, then your computer will burn up! People believed that myth for years. But experience, seat of the pants data not driven by profit, my own included, proves that to be untrue. It's the same with this ATF issue Matt.
Steviepoo,
Some of us still call the 41Te4 (not "41Te" as you said by the way) A604's out of habit, because we have been Chrysler owners a little longer.
One more thing Stevie. You really can be a nasty bitchy little whiner. So I don't know if you are really a *man* or not. Balls *or* no balls.