Preventive maintenance for A604 transmission

What's the best preventive maintenance schedule for the A604 transmission? What helps the most? If you use ATF+4, that makes it shift smoother, right? But does it make it last longer? If you replace the fluid often, does that really make a difference? If you replace the filter often, does that? Is replacing the fluid with ATF+4 more important than replacing it often? What about the diagnostic codes? Is it important to get them checked often, even when there are no obvious symptoms? How much does it cost to get the codes checked? Do you get a printout of them or what? Should you get someone to manually inspect the inside of the transmission even when there are no diagnostic codes? How can you tell if the person who does it is competent to notice pending problems? How much are they likely to charge for the inspection? Do they routinely do it when they change the fluid and filter?

If you call a dealer's service department on the phone and say "I want preventive maintenance on my A604 transmission", will they know what to do, and be able to tell you on the phone how much it will cost? Or do you have to give them a list of things to do? How reliable are most dealer service departments, for that kind of work? Are some of them likely to pretend they did preventive maintenance, because the person who does it might not actually know how to do it?

Another question about this transmission is whether your cruising speed makes any difference. In other words, even when it's not shifting, just going steadily in the highest gear, is there any significant wear and tear on the transmission? Or does the wear and tear happen mostly during shifting?

Reply to
me
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That depends upon you driving habbits and the load you put on the transmission.

No. If you use ATF+4, then your tranmission will work as designed! The A604 was DESIGNED to use either ATF+3 or ATF+4 depending upon which year it was made in. There are EXTENSIVE discussions available if you Google the history of this newsgroup.

Basically, most shops stock Dexron III trans fluid because it is cheap. Then they put it in your transmission with an additive called "LubeGuard". This additive supposedly modifys the fluid characteristics to match those of ATF.

The shop that rebuilt my A604 - which BTW will NEVER touch my car EVER again - had to rebuild my tranmission twice. I paid the first time, the second time was on warranty. They used Dexron III with lubeguard. I do not tink the failure was related to that, they said something about planetary gears.

Be that as it may, the trans did work after that. However it rean pretty rough. Hard shifts - especially downshifts. Not smooth at all. I was just praying real hard.

That was until I had the coil pack changed, and had them do the fluid change at the same time. This was a different, and very reputable shop. They told me that over the years they had never had a repair that was a result of using the Dexron III fluid - HOWEVER - they noticed exactly what I did, namely than when ATF+3 or +4 was used, these tranmissions worked much better "smoother" as it were.

This observation would be received here with mixed levels of acceptance. There are those here who have had horrendous experiences which they attribute to the use of the wrong fluid in the tranmission. So it is hard to say.

I will say this, however, if the DESIGN ENGINEERS say that you NEED a certain kind of fluid, don't you think it is in your best interests to just suck up the extra cost and USE IT??? My trans shop has. They feel that it is just good business practice to use the right materials for the job, and if it costs a little extra, but prevents potential warranty claims and premature failure (which would lead to poor customer satisfaction), then they are prepared to charge a little more and do the job right. They are CAA / AAA approved, and have a wall of "Thank You" letters from former customers, so they must be doing something right.

On balance of probabilities, I would say, Yes.

Yes. If the fluid breaks down, then it cannot protect the internal components properly. This will lead to component wear and premature failure.

You replace the filter when you replace the fluid. Beware shops that replace the fluid by tapping into the lines and circulating the new fluid in and sucking the old fluid out without droppong the pan to replace the filter. It costs more to drop the pan and replace the filter, but it is well worth it.

When my shop replaced the coil pack, they dropped the pan as part of the diagnostic porcess. Since the trans was in "limp mode" they wanted to see if there were metal bits in the pan. Even if your trans is not in limp mode, you want to check for this anyways!

You definiely want to change the filter. You would NEVER think to change your engine oil without changing the filter, why do this to save a few bucks??? If the filter is clogged, then the oil wont circulate properly - leading to loss of pressure, premature wear, and premature failure.

Just use ATF +4 when you replace it. How often you replace it depends on your useage level.

Well if the trans is running fine, there should be no codes as such. However, the computer stores data about things like fluid volumes used during internal transmission operations. At least this is what my shop told me. They said that the fluid volume used for my high gear shift was a little low. But after replacing the coil pack, they reset the computer, reprogrammed the trans and drive it for a while. When they double checked the values, they were all within limits.

So, by periodically checking the data in the computer, you could get a heads up that problems were on the way.

My shop will read the computer for free. Takes about 10 minutes. They do not require an appointment - just drop in.

They did show me the data display on their computer reading device (looked like a small hand-held scope with an LCD display).

If they drop the pan to change the filter they should have a quick look for obvious signs of problems like metal bits in the pan.

You can't.

They should, and it should be no extra charge.

Don't know. I don't trsut dealers any farther than I can throw them - ESPECIALLY with something like this. They charge "shop forman" rate, and put the must junior flunky on your car. If he screws up, then they say it was your fault, or they try to weisel out of covering the full cost of their mistake. They are also influenced by Chrysler not to acknowledge certain problems.

A reputable independant shop will not mince words with you about what is going on.

A CBC consumer show profiled a woman who had a piece of her tranmission litterally punch through the casing. When she talked to Chrysler, they said that they were NOT aware of the problem. When she went to a reputable shop, the guy knew EXACTLY what she was talking about. Said he repaired about 2 per week. And he actually had one in the shop at that moment. He explained, in detail, refering to the one in pieces what the problem was, and how easy it would have been to prevent the problem if a small piece was added to the transmission. They then tool the woman to talk to the head of Chrysler Canada's Engineering department. He knew exactly what she was talking about, but told her they were not prepared to help her since the van was more than 4 years old, and had more than 110,000km on it.

Chrysler KNOWS about the problems, but I suspect they have created a lovely little after-market cash cow that they have no vested interest in losing.

Like I said, I don't trust them, so I don't use them. I therefore cannot comment.

I doubt that. I think they would do the work. But the question is, did they do it properly?

I would say the wear and tear happens from a combination of bad design, and improper use. There is a higher probability that wear occurs during shifting, but it could happen doing "jack-rabbit" starts from a stand-still as well. It could also happen if the tires are allowed to spin.

In general, the ideal running condition would be to accelerate to fighway speed, set the cruise control, and never stop again. Even at higher speeds like 80 MPH, everything would read a steady state. Fluid would warm up and circulate, you would never downshift, and I bet you would go for 400,000 miles. Be interesting to make a test bed on a dynamometer and do this to see just how long the puppy would last.

The bottom line is, don't drive the A604 or 41te hard. Watch your mileage, and do your PM at a reputable shop. Change the fluid with ATF+4, and drop the pan to replace the filter. And don't tow heavy loads with the car. Do all this, and the trans will get a much longer life before major repairs are required. Fail to do the above at your own perril.

hth

Reply to
NewMan

...and practically guarantees the shop a steady stream of A604 rebuild business.

I think it easily could have been. Wanna find out why, in picayune detail? Go read this carefully, paying particular attention to how ATF+4 performs compared to Dexron and to ATF+3:

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They also said Dexron was acceptable.

Reply to
Daniel J. Stern

Typical "spinout" final drive failure....usually caused by excessive wheel spin in a stuck-in-the-snow situation. (The lady in the report lives in northern Ontario). The "small piece" referred to is just a bandaid fix retainer to prevent the freed up differential pinion shaft (because its roll pin has been broken) from totalling the case after the diff. pinions and shaft have already been messed up and welded together.

Just one of the disadvantages of housing the transmission and the final drive gears in a single box. A transaxle failure, yes...a transmission failure, no.

Reply to
cavedweller

Which is pointless because once that happens to the diff, the transmission is worthless as a core, it costs more money to buy all the parts to fix it up than for a trans shop to just toss it to the aluminum recyclers and get another one out of a wrecking yard to rebuild, that hasn't failed due to abuse.

Transaxle failure? That is like driving the car off a cliff then complaining that it's all bent up now and you can't drive it, must be a design defect.

No, not a transaxle failure, a user failure.

Ted

Reply to
Ted Mittelstaedt

No, you should always follow the SEVERE duty schedule in the factory shop manual with one caveat. If your using ATF +4 in a vehicle that came with ATF+3, the factory SEVERE fluid change schedule should be doubled. This is because ATF+4, being synthetic, lasts about twice as long as ATF+3. (at least, according to the factory manual)

No, the A604 will use either fluid just fine. The big difference is that ATF +3 wears out faster. Look at a transmission manual, there were no changes in the post ATF+4 years that were in response to the commencement of use of ATF+4.

There are some claims floating around that there were "programming changes" to the transmission TCM post-ATF+4 but Chrysler does not make public what the programming changes to the TCMs actually do, and in any case, the

1996-99 vehicles that came with ATF +3 as factory fill use the same firmware updates as the ATF +4 factory fill vehicles, at least, today they do.

The price of ATF+4 has gone down, and also Chrysler announced last year they would start licensing it to the aftermarket, so presumably the monopoly on ATF+4 will be broken sooner or later. Some individual dealers still are gouging for ATF+4 however. I think if you get it nowadays from a non-gouging dealer, that it costs double what ATF+3 costs in the aftermarket, so it is pretty much a wash on fluid costs between the two fluids now, there is no longer much incentive to use ATF+3.

No, they stock it because they cannot get ATF+4 from their distributors, they have to buy it from Chrysler, which is a nuisance. It also takes more space to store yet another fluid. The shops pass along the cost of the fluids to the customers so they don't care about the price, they probably would buy ATF+4 if they could simply tell their fluid dealers to stock it along with Dexron, that is why the announcement from Chrysler is so welcome.

The planetary gears are under high stress and are a common failure item, and you can get replacement gears from Chrysler or from the aftermarket - the Chrysler gears are more expensive but the steel in them is a lot higher quality. If yours broke, and they got cheap Chinese gears in there made out of putty it's no wonder they failed again.

coil pack, are you sure you don't mean selonoid pack?

I don't think so, I think everyone agrees that this is the case.

Not using ATF +3 or ATF +4 in these is basically a warranty violation since you are not using the manufacturer recommended fluid.

When the pan is off if your doing it yourself, you would be wise to take the pan to a trans shop to weld in a drain plug. The usual procedure around here is to drill a hole, weld a nut to the inside of the pan, then weld a washer on top of that, then screw in an allen-screw.

The result does not leave a drain plug sticking out the bottom of the transmission, inviting some road hazard to snap it off. And it makes fluid changes a lot easier since you don't have to take a bath in fluid when the pan comes off.

mileage.

The only thing you can really get a heads up on is clutch wear, but if you are driving it gently the clutches should last at least 100K miles, a few people have got 200K miles on original clutches, it is more likely something else in the trans will break first.

The only people that break differential pins on these are people that wheelspin. I've seen plenty of these transmissions in wrecks in wrecking yards, and only once have I seen one where the case was shattered like this. However it rarely snows here, that is probably why.

Also, add a trans cooler, this is important! The wrecking yards are full of them, just go find one and flush it out really good. Unless your driving in freezing temperatures, the trans fluid will never become too cold.

Just as a FYI, when I put my 94 T&C back together last year I initially plumbed in ONLY the accessory cooler (which goes in front of the radiator) and ran it like this for a month, because I wanted to be positive that there were no coolant leaks into the in-radiator-tank transmission cooler. Once I was satisfied with that, I plumbed in the in-radiator-tank transmission cooler UPSTREAM of the aftermarket air-cooler, and my transmission fluid temperatures rose HIGHER. My take on it is that the in-radiator-tank cooler really does little actual cooling.

Ted

Reply to
Ted Mittelstaedt

Sorry, I don't understand what's "pointless". If after "that happens" means the diff. pinion has punched a hole in the side of the case then the case is obviously shot.

If the pinion shaft is screwed up, and its roll pin is broken, but the shaft is held in position by the stamped ears that bolt to the carrier, (the "small piece" referred to by the poster to whom I responded originally) then the case is OK and could be reused. That's assuming that the differential distress is detectable and is detected by the operator before debris finds it's way into the transmission side and causes more problems.

I believe in the CBC story, the lady that complained bought the car used from a local dealer. That's snow country up there, and all bets are off.

According to the CBC program, the vehicle was behaving properly (I guess meaning that the transmission was shifting normally) and a loud "bang" was heard/felt and then the transmission (sic) was seen to spew its fluids all over the ground.

Sounds like a transaxle failure to me and I certainly didn't suggest there was a design defect. I thought my "..usually caused by excessive wheel spin in a stuck-in-the-snow situation.." might have indicated that. In that light, your cliff metaphor (?) is, well, curious....

Reply to
cavedweller

$22.05 (Cdn) per 4 liter jug at a southwestern Ontario dealer mid-March

Reply to
cavedweller

Wrong, wrong, wrongity wrong. Yes, it'll wear out faster, but that's the least of your worries with +3, which -- compared to +4 and to other fluids -- turns out to be a fairly shitty fluid in many critical transmission-protection performance criteria. Go look at Chrysler's SAE paper on trans fluid comparing Dexron, Mercon, ATF+3 and ATF+4. I posted the link earlier today in this thread.

Not really. They all have supply lines set up with local Chrysler dealers for dealer-only parts.

They can charge more for "special fluid" whether or not they install it.

DS

Reply to
Daniel J. Stern

Will a dealer's service department normally use ATF+4 without being asked, or do you have to tell them to use it? Will they normally use a good filter without being asked, or do you have to tell them what filter you want?

I know some shops would put metal shavings in the pan to convince you they should rebuild the transmission when it doesn't need it. But do dealers' service departments do that too?

If I look for a good independent mechanic, how can I tell when I've found a good one?

Reply to
me

Hmmm - looks like they removed that page, or something is otherwise wrong with the link.

Bill Putney (To reply by e-mail, replace the last letter of the alphabet in my address with the letter 'x')

Reply to
Bill Putney

Yeah, I put it up on an account that was due to expire later that same day. (Duh...!) Unfortunately, my main server is down. I'll post to this thread when it's available again, and where.

Reply to
Daniel J. Stern

I've moved it here:

formatting link

Reply to
Daniel J. Stern

That paper was written during a critical period:

1) Chrysler was trying to blame fluid for all their transmission failures that were really due to ill-designed parts 2) ATF+4 was only available from Chrysler and they didn't want to lose the money from people buying ATF+3 from the aftermarket.

There are lots and lots of "engineering articles" out there that companies produce which are nothing more than FUD designed to scare people into not buying or buying certain products. If ATF +4 was as available on the aftermarket as ATF +3 then Chrysler would have no financial incentive to lie about results. The fact that it is not is a gigantic financial incentive, even today, to lie, cheat, and compromise whatever engineering document you can, to get people to buy it. Even when the price is competitive with ATF +3 on the aftermarket, there's still huge incentive to get people to buy it because they are buying it from DC, not from the aftermarket.

As I said, look at a Chrysler transmission manual that covers the A604/41TE during the introduction of ATF+4. There were no internal design changes that were dependent on fluid. There were and have been lots of hard-parts changes of thickening parts to make them stronger, throughout the life of the transmission.

Ask any transmission rebuilder if the hard-parts falures of this transmission are due to fluid. A snapped weld on the sun gear isn't due to incorrect fluid, that is what happened to mine, and I posted pictures - anyone can see the weld is too thin for the power it is supposed to be carrying.

What Chrysler did with the A604 was designed it, and then as transmissions came back from warranty claims, they strengthened the parts that kept breaking all the time. In other words, everything in this transmission was designed too thin, and too weak, and Chrysler only bulked up the parts that kept breaking. During this time they also made numerous software changes in the TCM. What Chrysler DID NOT DO was to make everything much thicker and stronger than needed, then thin down the parts over the years that proved to not need the extra strength. And during the worst of the time period, Chrysler kept up a public relations campaign to blame everything other than their shitty design.

This engineering choice basically got the A604/41TE to the point where it would last through warranty period then once the warranty expired, everything you got past that was a gimmie. And I will point out that it is us, the owners, which discovered that frequent fluid changes improved longivity. Chrysler doesen't recommend fluid changes at the intervals that we all recommend for normally driven vehicles, only for "severe service" vehicles.

There's no question that ATF+4 is better than ATF+3. But there is a huge question whether the superiority of it really makes any difference whatsoever as compared to the hard parts changes in the transmissions.

During the time ATF+4 was introduced the a604/41TE had gotten a lot of hard parts improvements, so you cannot tell today if the increased longevity of the later A604/41TE transmissions is due to the better ATF+4 or due to the structural improvements in the transmission.

What I can say is that in my own 2 minivans, both with rebuilt A604/41TEs, that one of them is running ATF+3 and the other is running ATF+4 and there's absolutely no differnence between either in how they drive and shift.

What you got to remember is Chrysler is in business of making money off vehicles. What makes them the most money is if their products work perfectly until 100K miles then go kaput, so that the owners can't sell them to the used car market, and the depreciation has made them not cost-effective to repair, so the owners have to go buy new ones. Chrysler loses money if their products are made so that they last forever, and are easily serviced and supplied by anybody -other- than Chrysler.

Ted

Reply to
Ted Mittelstaedt

were really

Chrysler *dealers* were trying to do so, certainly ("You didn't use genuine Chrysler fluid; it's your fault"), but Chrysler *Corporation* was not. Witness the numerous TSBs and engineering papers talking loudly and publicly about engineering improvements to transmissions and their components and control equipment specifically to improve durability.

Sure, Ted, it's all a part of a vast Chrysler Corp. conspiracy, coverup, lying campaign, etc.

Even if one were able to get that kind of information from a "transmission manual" (which one cannot), you display here an incomplete knowledge of what components are dependent on fluid.

Now, how would *YOU* know that? I mean, considering Chrysler went to such great lengths to cover them up and keep them hush-hush and blame everything on the fluid, and all...

It can be, indirectly. Heat and friction, bud!

There are faulty large welds and high-strength small ones. "Anybody" can see nothing of the sort.

Pretty much, but your claim that the superiority of ATF+4 is a vast, giant, enormous disinformation/distraction campaign is just...silly and ignorant.

Well, *DUH*! No automaker does that any more. They can't! Not and still meet their weight and fuel economy goals. Such is the price we pay for the way our regulations and market preferences have evolved.

Finally. That wasn't so hard, now, was it?

Such a huge question may exist in your mind, but that doesn't mean it exists elsewhere.

Your butt is not a sufficiently sensitive test instrument.

Did you graduate from high school with that English?

Here we go again with the conspiracy theories...

Reply to
Daniel J. Stern

Thanks! If you don't mind, I will post the link on the 300M Club forums.

Bill Putney (To reply by e-mail, replace the last letter of the alphabet in my address with the letter 'x')

Reply to
Bill Putney

Point taken!

Reply to
NewMan

Ack! My bad. Sorry about that, you are quite correct.

I think I am going to look into this. I will be fully loaded and travelling through the mountains this summer. You just cannot be too careful, and I want to get maximum service life out of my trans. Sounds like a booster cooler is cheap insurance.

Reply to
NewMan

ATF+4 does NOT make shifts smoother than ATF+3. Functionally they are equivalent and are NECESSARY for the 604/41TE/42LE transmissions to work correctly, but ATF+4 is a superior version of the fluid. Dexron is not an adequate fluid for the transmission under any circumstances.

After reading the SAE papers on ATF+4 versus ATF+3, my gut feeling is that about half the problems with the 41TE transmission were due to the fact that ATF+3 had an EXTREMELY short working life for a transmission fluid. Oxidation rates and additive breakdown rates in that fluid were very high, so it had to be changed very often to maintain the concentrations of the additives needed for the transmission to work right. ATF+4 fixes both problems, and should not only make the transmission last longer it shouldn't have to be changed nearly as often.

Reply to
Steve

Actually, I'd prefer if you can host it on club forum space (or somewhere else)-I need to clear stuff off my server to make room for new stuff. D'you think that'll be possible?

Thanks DS

Reply to
Daniel J. Stern

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