Re: Preventive maintenance for A604 transmission
- From: "Ted Mittelstaedt" <tedm@xxxxxxxxxxxxxxxx>
- Date: Fri, 31 Mar 2006 13:29:45 -0800
"NewMan" <CloakedRun2001@xxxxxxxx> wrote in message
On Fri, 31 Mar 2006 02:28:55 -0500, me@xxxxxxxxxx wrote:
What's the best preventive maintenance schedule for the A604
That depends upon you driving habbits and the load you put on the
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
What helps the most? If you use ATF+4, that makes it
shift smoother, right?
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.
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
vehicles that came with ATF +3 as factory fill use the same firmware updates
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
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.
There are EXTENSIVE discussions available if you
Google the history of this newsgroup.
Basically, most shops stock Dexron III trans fluid because it is
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.
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.
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.
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
coil pack, are you sure you don't mean selonoid pack?
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
I don't think so, I think everyone agrees that this is the case.
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
Not using ATF +3 or ATF +4 in these is basically a warranty violation
since you are not using the manufacturer recommended fluid.
But does it make it last longer?
On balance of probabilities, I would say, Yes.
replace the fluid often, does that really make a difference?
Yes. If the fluid breaks down, then it cannot protect the internal
components properly. This will lead to component wear and premature
replace the filter often, does that?
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 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
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.
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
Is replacing the fluid with
ATF+4 more important than replacing it often?
Just use ATF +4 when you replace it. How often you replace it depends
on your useage level.
What about the
diagnostic codes? Is it important to get them checked often, even
when there are no obvious symptoms?
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.
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.
How much does it cost to get the
My shop will read the computer for free. Takes about 10 minutes. They
do not require an appointment - just drop in.
Do you get a printout of them or what?
They did show me the data display on their computer reading device
(looked like a small hand-held scope with an LCD display).
Should you get
someone to manually inspect the inside of the transmission even when
there are no diagnostic codes?
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.
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?
They should, and it should be no extra charge.
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?
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
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.
do you have to give them a list of things to do? How reliable are
most dealer service departments, for that kind of work?
Like I said, I don't trust them, so I don't use them. I therefore
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?
I doubt that. I think they would do the work. But the question is, did
they do it properly?
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?
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.
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
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
no coolant leaks into the in-radiator-tank transmission cooler. Once I was
with that, I plumbed in the in-radiator-tank transmission cooler UPSTREAM of
the aftermarket air-cooler, and my transmission fluid temperatures rose
My take on it is that the in-radiator-tank cooler really does little actual
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