ATF+3 ATF+4 Dexron TCM replace

Here we go again.
1994 Plymouth Voyage "3" liter Mitsubishi, rebuilt tranny with 58,000
miles

Rebuilt at Cottman. What fluid they put in 4 years ago? Who knows.
Asked if they updated the software for the TCM, Transmission Control
Module, what's that?

Car has the famous 37 mph shudder, wrong fluid and bad software
update.
Thanks to Chrysler techs on this forum who posted and emailed me on
that.

The TCM is $190 remanufactured at the dealer. Any cheaper? Can I
replace that or is that a hard thing to do? Appears to be a dealer
part. At least would get the right one with the software update or
really firmware update.

This can't be flashed if I read the TSB right.

Anyway to tell easily is Dexron was used in case of the proper ATF+3
or 7176 or whatever is supposed to be used. ATF+4 is the synthetic
version, better or what?

So many questions, sorry.

 

Any wrecking yard TCM that has fins will work. You can get one for $100 at
a wrecking yard then the dealer can charge you $90 to flash it. That is
assuming
they still have the flash tool and a tech that remembers how to use it.

Any of the finned ones can be flashed.

flush and refill with atf+3 or ATF+4 whichever you prefer.

Ted

 

use it.

So the same cost. And although the fins are flashable, what about
cables and connectivity. I asked because one tech said $125 for a
rebuilt controller but NAPA does not have these and the dealer is
$190 which sounds, in this case, a bargain, if it's upgraded as
purchased.

I asked the dealer and they said $70 to see if my existing TCM
can be upgraded. I wonder if I should ask them if they will
charge for something that had a TSB, although long ago, and
probably resulted in many failed transmissions (electronically
controlled clutch was shifted too slowly causing stress on the
torque converter and self-destruction) and the wrong fluid.
Dexron is not right and is mentioned in official manuals and
places way back then. I'm told it's even on the dipstick but I
have not looked.

What type of flush? A little flush or a big flush? I have been
warned by the Chrysler dealer AND Cottman Transmissions not to
flush this old tranny because the dirt is keeping it together.
Well, it's a rebuilt, 190,000 miles with 58,000 miles on the
rebuilding by Cottman (correct fluid and TCM upgrade - who knows,
they don't.)

So is there a gentle flush or do you mean a reverse power flush.
The destruction is in the details. I am sorry to ask so many
questions but I find I make too many mistakes if I don't
over-ask. Some people can get by with broad answers. I am not one
of those lucky people.

If it's a little flush, if that exists, then it won't get the
fluid out of the torque converter which is seperate? You don't
mean just drain but a flush, yes?

It's not a question of preference, unfortunately. The ATF+4 is
synthetic so lasts longer and does a better job. But my seals are
old, 10 years old, and there is at least one reference, justified
or not, that the ATF+4 might cause possible seal leakage on these
old transmissions which were designed for ATF+2, and then ATF+3
which is non-synthetic.

The ATF+4 is probably a little bit more slippery which is fine in
my case. It's not fine if it nudges a seal to leak.

So that's my quandary. Any thoughts?

Thanks for your reply, Ted.

 

Well, that was somewhat of a joke - you really should call around.
If the wrecking yards in your area are full of them then maybe you
can get the trans computer for $20.

They are all the same, they use the same harness. '89/90 have to have
a wire cut with the newer firmware.

According to the green "Service/Diagnostic Procedures & Refinements Manual
for the
41TE/AE Transaxle" by Chrysler, on page 32, 1993-1995 original trans
controllers
were finned with 4 heat sinks and are flashable. To flash they require
Miller CH 5500
flash kit, as well as a DRB tool and a special cable.

It was only the 1989-1992 controllers that were non-finned and
non-flashable.

Yours is probably flashable. By the way, the fins are along one edge.

Well, the vehicle is out of warranty so they are legally not
obligated to do squat. I think you should just call the dealership
and ask their service manager if they have the special tools and
a tech that remembers how to flash the '93-'95 transmission
controller, then pay them the $70 to just flash it. After all it
isn't like they just plug in and have at it. The DRB tool itself
is like around $10K also. The tech is going to
have to dig around in documentation and such to make sure
he's got the right firmware. And of course, like any computer,
there is always a slight risk when your doing a firmware update
that your going to scrooge the controller because an error
happens when it's rewriting the PROM. If that happens then
the TCM they got on the shelf is going to go into your car
and you will end up doing a lot of yelling, and they probably
will end up eating the labor on the whole deal.

I very much doubt that it was still in the manuals for 1994. I
know that Dexon was listed on the dipstick for the '89 models
but I think even the owners manual mentioned Type 7176 back
then. I doubt also that it was on the dipstick in 1994, it isn't
on the dipstick in my 1995.

This type:

http://www.allpar.com/eek/atf.html

That is baloney. Read the following:

http://www.allpar.com/fix/trans.html

Keep in mind that this transmission uses a fluid filter that uses a
felt-like material, not
a screen like some transmissions do. Chrysler really meant business when
they
designed the filter for this. The fluid must be absolutely clean. There
are many small
passages in the valve body and even small particles are going to jam it up.

Do not reverse power flush. Unfortunately some shops have invested
heavily in flushing machines that they want to use to make money with
and are so turning a simple procedure into a more complex one and
charging a lot for it. I frankly recommend that if you change
your own oil that you do your own trans flush on these transmissions
as well as change the pan gasket and the pan filter.

The factory calls for RTV sealant on the trans pan, and they do this
for a reason. Most DIYers use cork or composite gaskets, I did
myself. However, I have discovered in mine that the pan and gasket
only hold their seal for about 2 years. Then the gasket shrinks, or the
bolts get loose enough, that it starts leaking. Once you see it start
to leak then retorque. RTV would not have this problem. Since I
change my own oil I am underneath the engine every 3000 miles and
so I am able to catch small leaks like this before they turn major.

The method I documented on the website above gets all of the fluid.

If it was rebuilt then the seals were replaced and are of newer material.
But you aren't required to use ATF+4 on your vehicle. ATF+3 is
about a quarter of the price and is available from retail, while ATF+4
is only available from the dealer, so that made my decision for me.

The two ATF+'s are of the same frictional coefficient.

Get the TCM flashed and then change the fluid.

Ted

 

I agree with Ted, but three additional comments:

Make sure you clean the pan completely while you have it off. You will be
amazed at the amount of crud that accumulates there. I use brake cleaner
after I have wiped it out completely and scraped off all the old RTV gasket
material. Also, clean the magnet completely at the same time and then
reinstall in the same place.

Second, don't bother with using a cork gasket. The dealer sells a composite
metal and silicone gasket for these transmissions. It is a bit pricey, but
is re-usable up to three times and I have not had mine leak when all bolts
have been torqued to the specified 165 inch pounds.

Third, I use ATF+4 from the dealer, but purchase it in the gallon container
as it is cheaper. If you search you can find a web dealer that sells at
discount. I have used Galeana Chrysler Jeep in SC. Compare to local dealer
prices and ask what volume will get you a discount and how much.

Bob

Lots of really good advice removed.

 

Whoops, you used a franchised transmission chain. These places specialize
in deciding that transmissions with minor problems need expensive total
rebuilds. These expensive total rebuilds are always charged for, but
frequently not actually done. You should have taken the car to a competent
independent transmission diagnostician first.

www.car-part.com , searchable used auto parts nationwide. Get a '95 or
newer TCM.

That's why you should get the newer one, with the finned case, which can
be flashed.

No. Call Cottman's and ask, but most of those places use a universal fluid
with additives claiming (but failing) to convert the universal fluid into
the right stuff.

 

I did not take the car, the previous owner did to Cottman and was
most unhappy. So you're right. $2000 for the rebuilt then another
$700 for parts, pumps, not rebuilt right, in 2000. I suspect the
TCM or EATXII or whatever they call that Transmission Computer
Module was not upgraded. It still has the rough shift around 37
mph, the notorious shudder. After a tune-up, it's better. The
distributor had a corroded wire which probably screwed up
everything electrical. The tune-up, which I did not ask for, just
get the start problem, the original distributor wire, was $341,
which I thought was expensive and was something I used to do,
tune-ups. But the tranny is working much better, the shudder is
down about 90%.

So now for the software upgrade and the fluid change. I have not
been able to get through to Cottman on the phone. But I can see
the conversatio now - back in 2000 what fluid did you put in and
did you upgrade the computer? Probably no to both. Nothing on the
original bill about anything with a computer.

Thanks for your response.

 

Read about that wire #49, so thanks, not my problem.
Have found thanks to Daniel Stern, some yards that have it for
$25 to $35 and may be near me in case I do not use my original
one. Tempted to have the dealer do the flashing and resetting the
computer but found the method in allpar or somewhere else for
resetting the TCM after the upgrade. Maybe the main computer too?

one edge.

Thanks, found it, see the fins and checked the TSB's and the part
number and it's flashable.

R4686478AA 04686606 93-94 A,C,J,P,S,Y 3.0, 3.3 & 3.8
from the TSB, above is the remanufactured part and software
upgrade from the dealer. I have the "S" Voyager model which
probabl is the "AS" model in 1995 that you recommended for the
TCM.

4686131 was the original part number but I can't read it.
Probably on the metal tag and I don't want to take it off the
firewall just yet.

Thanks, so a flush using the transmission pump I gather would be
just fine, instead of the power flush.

They probably thought I meant the reverse power flush only. They
could have mentioned the ordinary flush. It's similar to their
fluid change which uses the tranny's pump. I just want the fluid
out of there. Okay the torque converter is sealed but still.

Hmmm, thinking, if I push the OD button and disconnect the
OverDrive, might that help the torque converter by disconnecting
the lockup? Don't know, just a thought. Read one fellow who did
it with soldering and tinkering. In any case, the 37 mph shudder
is not the lockup situation which probably occur at highway
speeds.

to jam it up.

That's very helpful. Dealer said not necessary if 30,000 miles.
But this is a rebuilt and questionable and probably worth the
extra expense.

fluid.

Even the torque converter too? Sounds like a good method. I have
used that in the past so familiar with the siphoning. Just don't
have the confidence and a garage now with ramps but I am thinking
about it.

material.

But it's Cottman, so my confidence is low having seen how they
charged the previous owner at least $2700 and that owner, my
friend, was still most unhappy with the performance of the van.
Rebuilt in 2000 but not leaking, still don't like some of the
feel and subtle sounds of the tranny. So have been babying the
car. There's the slight shudder at 37 mph and at 70 mph, hear a
slight whine. Does not sound quite normal. Now I have had
Chrysler trannies that whined for 130,000 miles. I drove Chrysler
trannies that ran dry, DRY!, put in fluid, and the thing was up
and running so in the past, they built stuff that was tanklike.
Everything else came apart, the body, the electrical system,
everything but loved those slant-6's and their trannies.

Thanks for the excellent advice and taking the time to go into
all these details, most kind of you, especially the good advice,
get the TCM done FIRST and see if it affects anything. If not,
then some have gotten a quieter, shudder-free tranny with just a
fluid change. Mine is quiet at the moment with just a touch of
shudder at 37 mph after a tune-up where the distributor wire was
shot and screwing things up electrically all over.

 

Resetting the TCM and flash-updating it are two different things.

Don't. Let the dealer do that if they need to when you have them
flash-update it.

No the torque converter is not sealed. Fluid is pumped into and
out of it. If it was sealed the fluid inside it would overheat.

No. Don't do that.

You probably have Dexron+Lubeguard not ATF+3 in there.

Look again at how much space they had to work with. The
FWD layout is not optimal. The trans is crammed into the
engine compartment. I'm all for newer materials and such
but there' s no substitute for meaty, beefy, thick components.
And there is no space for that in a FWD. So, they try to
get around the lack of space by making everything thinner
out of fancy materials. Sometimes it works, other times
it don't.

Ted