Symptoms of a failing tranny?

'93 Grand Voyager, 3.0L, 3 speed auto (Dad used to say it was the four speed
O/D, but it doesn't have O/D on the shifter, cruising at 100kph is at around
3k revs, and I only feel three shifts so...). I know some trannies in these
vans is known to drop at 180k kms on the dot, I'm sitting at 178k and
getting worried. The 1-2 shift has always been rough since new, now over the
past six months or so the 2-1 downshift has been grabbing. Do I have
problems on the horizon? I'm planning on dropping the pan and changing the
fluid and filter the next chance I get. I just haven't heard of an auto
grabbing on it's way out before.

 

The 3 speed is pretty reliable, at least compared to the 4 speed. Old
fluid can make them shift pretty rough - changing the fluid may well
get rid of the problem.

 

The O/D is not on the shifter. It's a switch to the right because it's
electronic, that is, an electronic transmission, controlled by a TCM or
Transmission Control Module, and not a selectable gear. The TCM is a computer
which can have its firmware upgraded by the dealer. It's easy to miss the
switch. Took me a long time and I also erroneously thought I did not have a
4-speed O/D tranny.

You might want to consider checking to make sure you have the latest firmware
if, I repeat, if this is the case with you. In other threads, in the last few
weeks, I spelled out the modules and the firmware versions.

Are you thinking the shifter will say 1 2 D O/D or something like that? It does
not. I made that mistake too. The VIN might sort this out for you. Don't know.

In my case, the firmware solved the very uncomfortable shudder of the
transmission beginning to self-destruct because the clutch was engaging too
slowly the torque converter. A software mistake with the early transmissions
that was found and first corrected around 1995 or so in the tech reports.

I had the pan dropped, the filter replaced with OEM, and used ATF+3 and all the
previous problems immediately went away. To upgrade the computer is relatively
inexpensive. In fact, the whole thing at a super good dealer was around $130
USD. But be careful. Another dealer could easily charge double and maybe not do
such a hot job. Ask around. In my area, I could not find a non-dealer mechanic
who really knew or wanted to be bothered by all this which requires special
cables and the equipment to flash the EEPROM in the TCM in the pre-1995
Voyagers. And my local dealer was a bit of a jerk so I found a distant dealer
who was great, from cartalk.com. Heh, what's a guy going to do when he can't
get a straight answer?

Oh, when the car goes into O/D, the engine actually slows down as I just
discussed tonight, as a matter of fact. Paradoxically, the highest gear does
not need a very fast engine since it's directly coupled. That's why Over-Drive
works so well in efficiency. Now am I right or do I have to go into hiding?

And I also only feel three shifts. But a fellow I was discussing this with who
used to fly airplanes, so is careful about engines obviously, and be an
electronics repairman said that the fourth shift is when the engine slows down.
So it's not obvious and even counter-intuitive. In fact, it's the obvious of
what you might expect going into fourth gear.

How am I doing? On target or not even in the universe?

 

hiya,

I had the rough downshift on my Granada (UK) when the donkey was sick and
the idle speed was too low, raised the idle speed and the downshift was
lovely again.

m

 

He won't have the switch even if it's a 4 spd. I believe it may be as he
says feels 3 shifts 1-2 = 1 2-3 =2 3-4 = 3. If it was a 3spd it would only
be 2 shifts.
Larry

 

Treeline wrote:

So you'd see it on a tach but not feel it - because it isn't going to go
into O/D under an acceleration condition. It's like that on my Concorde
(that has a tach).

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

 

The 4-speed auto shift quadrant says "P R N D 3 L".
The 3-speed auto shift quadrant says "P R N D 2 1".

Using that ID guide, which transmission is it?

The "3 shifts" you feel could either be 1-2, 2-3, 3-4, or could be 1-2,
2-3, and the torque converter locking up in 3.

This "knowledge" is not correct.

Not normal.

Define "grabbing".

How often have the fluid and filter been changed and, if it's the 3-speed,
the bands been adjusted and the linkage adjustment checked?

 

He won't have the switch even if it's a 4 spd. I believe it may be as he

Crap sorry, I meant two shifts. I'll make sure today. )

 

The 4-speed auto shift quadrant says "P R N D 3 L".

That'd make it the three speed I do believe. I'll have to double check.

Crap I think I should've put two shifts. I'll make sure this afternoon. Like
I said, on the highway at 100kph she's sitting at just over 3000 rpm. That
sounds pretty high if it had an O/D tranny does it not?

I've heard it several times from several sources....

Again, not the only occurance I've heard of...

Grabbing. Upon deceleration (foot off the gas, on the brake) when the tranny
downshifts to first the tranny grabs, the revs drop a few hundred rmp, the
vehicle lurches forward a bit due to the engine acting as a brake in this
case. Grabbing.

To be honest, not very often. This was Dad's van before he passed and he
really didn't keep up with maintanance which I'm paying for now (those rear
brakes I finished up yesterday were a pain in the ass but worth it, I also
noticed two completely rotted out tires). There really hasn't been a hell of
a lot of kms put on it since the last ATF change, although I don't know
where he had it done or which ATF they used (Chrysler-specific or not). It
hasn't been a daily driver in years.

 

Lots of people heard "The earth is flat" from lots of sources lots of
times.

Sounds like a kickdown cable and band adjustment issue.

Do so now.

DS

 

Alright. Definitely two shifts, first at 40kph, and second at around 75kph.
"D 1 2" on the indicator. 100kph at around 2800 rpm. All signs point to a
three speed.

 

I know some trannies in these vans is known to drop at 180k kms on
the

Until proven otherwise. Right or wrong, it's still a well documented
issue (or non-issue, as the case may very well be).

I'll adjust the bands while I do the fluid/filter, tomorrow with any luck.

Tomorrow will have to do.

 

Does this mean that "D" represents exactly what?
The full spectrum, whatever that might be, from 1 to 4?
Or from 1 to 3 and Overdrive then which is the torque converter lockup?

And the "3" is used for what used to be the "2" - for
icy conditions as the start gear? Or is L really 1 and maybe 2?

If it's "4" then the torque converter may or may not be locking up?
"4" is not automatically Overdrive? It's possible to have Overdrive
in either of the two configurations above? So if it were a 4 speed
plus Overdrive, is that then really a "5-speed" ???

I don't have an owner's manual and the factory shop manual won't arrive
for another week for a Voyager 3.0 L with the 41TE/A604 tranny.

Heh, thanks to the give and take on the group, I did find a shop
manual for $20 plus shipping or $25. I guess selling a manual
when people needed to get their taxes done is not a great time
for the seller, but good for the buyer. Generally the manuals sold
for twice this but this one looked a bit worn on the cover though.
But as long as it's readable.

 

Yes. 1-2-3-4, with torque converter lockup in 2, 3 and 4.

Overdrive is not the same as TC lockup.

No, 3 is used to prevent the trans from shifting into 4th (overdrive), and
it also raises the 1-2 and 2-3 shift points and the road speed at which
TC lockup occurs.

L dramatically raises the 1-2 shift point, and even more dramatically
raises the 2-3 shift point, and prevents TC lockup in 2.

4th is an overdrive gear. Do you understand what that means?

It is not a "4 speed plus overdrive".

DS

 

So it's not possible to start the car in second gear as it used to be with
"2" presumably for snowy or ice conditions where less torque was
preferable. I rarely used "2" and it did not seem too different from just
going a little more slowly in "D." So they just dropped the snow/ice gear?
Or is it "3" since it raises the shift points?

Let's see if I can remember this stuff again.
4th appears to spin the drive wheels rather fast compared to engine speed,
hence the name, overdrive. I get this confused with torque converter which
is locking the tranny to the drive wheels in whatever gear is being used
except for first gear? A torque converter lockup in 4th gear would produce
the highest gear drive wheel ratio compared to engine speed?

And 3rd gear should stop before 4th but I don't know the specifications,
without a manual. Maybe 3rd is good until 70 mph and 4th goes
as fast as the engine or vehicle can tolerate. Or possibly 3rd is good
to go to even 90 mph. Just guessing.

Probably looking at the actual gear ratios would make this all a bit
clearer. When I get ahold of a shop manual, I'll look it up for the
A604/41TE for the 1994 Voyager 3.0 L.

 

MOST back then had the OD on the shift quadrant. Pre OBD2 most
firmware was not upgradeable.

$ gears IS 3 shifts. You start in 1st - it shifts to second (shift 1)
third)shift 2) and overdrive (shift 3)
In between the TC also locks in both third and overdrive - so you can
feel 5 shifts if you reallu concentrate.

 

Don't forget the TC lockup.

 

I am not sure what you mean by the above.
My gear selector says "P R N D 3 L" - where would be the OD? Is that not
embedded in the "D" which means gears 1 through 4 with 4 being OD?

There is an electronic switch, below the rear windshield wipers' switches,
which allows the O/D to be turned off. This is on a 1994.

About Pre OBD2, that depends. The rough rule of thumb is that if the TCM has
dual fins, then it has an EEPROM instead of an EPROM, hence, flash or firmware
upgradeable. The vans in my range, pre-1995, require a special harness to be
attached to the device which does the readings and the upgrades. The extra
equipment required for the upgrading is why I decided to just go to the dealer,
a big dealer, who would have all these extra, older devices and capabilities.
It's all a bit confusing but I posted a list of years and what engines and body
styles can be upgraded going way back, to 1989? It's from the TSB's. Since the
TCM is obviously electronic and EEPROMs had been around for some time before
this, it's not unusual to find a TCM and A604 tranny with a flashable TCM.

Some of the cars had EPROMs instead of EEPROMs, so I don't know what they did.
Maybe they did not need any firmware upgrades. If they did, they would have had
to purchase, I assume, an upgraded TCM which is relatively expensive compared
to flashing the EEPROM.

 

It has never been possible to start the car in 2nd gear on an
automatic Chrysler product. Some Fords over the years offered this
ability.

Driving in slippery conditions is best accomplished in the highest
possible gear.

Right. Underdrive means the engine is turning faster than the
transmission output shaft. Direct drive means the engine is turning at the
same speed as the trans output shaft. Overdrive means the engine is
turning slower than the trans output shaft. NOTE this does not account for
the final drive, which on a RWD vehicle is external to the transmission
(in the rear axle) but which on a FWD vehicle is internal to the
transaxle. This is always an underdrive ratio, in that the input shaft
(which is the transmission's output shaft) turns faster than the output
shaft (i.e., the wheels).

No, when the TC locks it creates a direct connection between the engine
and the transmission input shaft, to eliminate the slippage that is
present with an unlocked TC, that's all.

That's unique to the electronic 4-speed and certain other electronic
transmissions. Most ordinary automatics lock the TC only in the top gear
(whatever that might be, 3rd or 4th) and only above a certain road speed.

Correct.

DS

 

Actually the Chrysler "Autostick" 4 speed transmission allows you to start
in second and is a very nice feature for snow/ice conditions when coupled
with the 3.5L since the accelerator tip in made it difficult to not spin the
wheels in slippery conditions.

Bob