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?

 

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

 

....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:
http://www.engin.umich.edu/~dastern/cars/982674.pdf

They also said Dexron was acceptable.

 

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.

 

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

 

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.

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

 

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....

 

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

 

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

 

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?

 

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')

 

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.

 

I've moved it here:
http://u225.torque.net/cars/tech/trans/982674.pdf

 

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

 

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...

 

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')

 

Point taken!

 

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.

 

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.

 

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