strange transmission problem and theory

1989 grand voyager, around 200,000 miles, runs great, used to drive
perfectly until this morning. No fault codes displayed on dashboard.

I have had several Chrysler minivan transmission failures, so I'm
familiar with the classic symptoms. This transmission is different. It
doesn't leak a drop and there were no warnings, it was a sudden
problem. My wife was driving. She described a whining noise, then the
transmission stopped transferring power, as if it had been placed in
neutral. After a short while it would have a burst of action and then
stop again. She managed to drive in short lurches and get it parked
safely off the street.

After work I arrived with a tow rope but decided to see what the van
would do. I heard the mild whining noise. The van backed up, then went
forward normally for about a hundred feet or so. After that it would
cut out, then it would lurch forward again. After a short time,
nothing. So I towed it home.

Here's the odd part. I used to have another van that leaked a lot of
fluid before I sold it to somebody who really wanted to fix it. When it
was low on fluid, it would get starved for fluid whenever I stopped
suddenly, presumably because the fluid would all lurch forward. Then
when the traffic light turned green I would rev the engine up and it
would just sit, until it had sucked up enough fluid again and then it
would lurch. This is exactly the same feeling I got today from my
current van, the only difference being that the current van in question
is properly filled with the proper fluid. The strange thing is that
when I pulled the dipstick after driving 100 feet, I noticed a lot of
little tiny bubbles in the fluid on the stick, as if the transmission
had been sucking air. It also occurs to me that air in a hydraulic
system can cause a whining noise.

Here's my theory and question. Is it possible that the filter may have
fallen off the bottom of the transmission into the pan, rendering the
transmission unable to pick up fluid? Could this account for the little
bubbles on the dipstick? Is this even remotely possible? I understand
that this filter is held on by a small bolt, so it seems unlikely that
it would fall off. But I have never had this transmission apart, which
means that somebody else put the filter on. I don't have a problem with
taking the pan off. I just wondered what you guys think of the symptoms
I have described. Can you think of another reason why a van might act
as if it is starved for fluid and have tiny bubbles on the dipstick?

 

Definitely worth a try. What have you to lose?? The theory sounds
plausible.

 

That's how I was approaching the situation. I'll certainly open it up
tomorrow after work and see what's going on in there. I just can't
think of any other good reason why it would do what it's doing. There
are a few weird things about the situation. It seems like when a
transmission is failing, it will wait for a moment and then get itself
together enough to start going down the road. This one will go at full
power and then stop.

 

Other info please? Transmission rebuilt previously and when? Fluid and
filter changes at what intervals? Which fluid was used? Any other symptoms
or error/diagnostic codes? Did you check the fluid level? Was it possibly
overfilled causing it to whip up the air bubble mixture? Was it low?

Bob

 

As it turned out, the reason why the transmission couldn't draw fluid
was because of a clogged filter. I changed it and the fluid, just to
see what would happen, and the van ran great again, for about 30 minutes
and about 20 miles. Then it had another attack. This morning I decided
to see what it would do, and now it won't do anything in reverse, but
forward is normal except that it gets starved and quits, just like it
did the other day.

Now I'm thinking that although it has lost its reverse gear, if I
replace the filter again it would probably go forward, just like another
van that I used to have. I used to drive that other van all over town
and it worked normally, but I just couldn't back up.

I'll replace the filter again and see what happens. I'd much rather
have a no-reverse van for the cost of a filter change or two than to
replace the entire transmission, at least for now. After I get a spare
vehicle I might go ahead and tear into this one and see about getting it
to work normally.

 

Hi Robbie,

I think your just wasting fluid. I think what's happened is you have
had a gear failure, such as the front sun gear that failed on my
transmission, a pic of it is here:

http://www.freebsd-corp-net-guide.com/94tcpics/fig52.jpg
http://www.freebsd-corp-net-guide.com/94tcpics/fig53.jpg
http://www.freebsd-corp-net-guide.com/94tcpics/fig54.jpg

If the trans was in limp mode then you would have reverse.
No reverse means something is broken and you have metal
fragments throughout your trans lube system.

At this point, if you keep pushing it your taking a risk that
your going to bind up something hard at speed and the
transmission is going to grenade itself, and be completely
worthless as a rebuildable core, so if you ever do want to
get the thing fixed your going to have to pay even more
money. However there's a minor possibility that this has
already happened, and there's also a small possibility you could
nurse another year out of it - if your intending to just take
it to a wrecker when the transmission finally dies, then you
might not care.

If you feel up to it, a trans replacement is not that difficult
espically on a FWD van, why don't you call around to
wrecking yards and see if there's a good transmission out
there?

Ted

 

You could be right, but I did put about 50,000 miles on the other
no-reverse transmission before it died. I thought it was worth a try
with this one. There's a junk yard nearby that sells transmissions for
under $100. The only problem with that is that you don't ever know
whether it's a good one or not.

I took the pan off again, and it is full of shredded metal, after I
cleaned it out thoroughly Wednesday. I'm wondering now, if it has a
bunch of chunks on the bottom but it still drives forward and shifts, is
it likely to lose the forward gears as well, or could it work just like
my other van?

 

The luck of the draw.

Te

 

the pump is losing prime take it in and have it replaced before a total
rebuild is needed

 

Here's the end of this story. It went forward for about 50 feet and
then quit, and now it's finished. I'll have to decide whether to put
another transmission in it, or if I just want to sell it for cheap to
somebody else who wants to put another transmission in it. It's a nice
enough van, an 89 Grand model with all the accessories and they all
work. Tough choice...

 

It depends. Does this have the 2.5 Turbo or the 3.0 Mitsubishi? If
it's
the 2.5 Turbo, then by all means, hang onto it. You have the
non-electronic 3 speed transmission and that combo is desired by
turbo minivan fans! You can rebuild that sucker, boost the boost
and take it down to the local dragstrip and collect pink slips all
night long if you have a mind to do so. ;-)

But if it's the 3.0 Mitsubishi, which if it hasn't had the heads
rebuilt, it will
need it soon. I'm gonna assume it's the 3.0L with the Ultradrive.

89 Ultradrives had a LOT of parts changed in them in later versions,
here's a list of some of the majors:

early '89 had 3 sealing ring reaction shaft, was updated to 4 sealing
rings in
late 89

revised input clutch hub

parking sprag bracket changed from stamped steel to casting

cooler bypass valve added in late 89

O/D piston upgraded to 4 slot pistion in 1990

10" torque converter introduced for the 3.3/3.8 ion June 1990

1990 input clutch upgraded to more durable

thicker transfer shaft in 1991

input shaft spline changed from 24 tooth to 22 tooth in 1991

new transfer gear design in may 1991

new valve body in 1991

CCD bus system introduced in 1992 - the TCM for 92-95 is different
than 89-91

1993 removed speedo pinion bore, went to electronic speedo

more durable bonded clutch disk in converter in 1993/1994

differential gearing changes in 1993

And a word also about the transmission computer. If yours has the
original computer, that computer needs to be replaced with one that
has newer firmware. For the 1989 year and 3.0, the number to use
is 4796121. If your trans computer does not have this part # it is the
original one, and that firmware has a bug that causes the transmission
to prematurely wear.

the cheapest and probably best way to handle this one if your going to
keep it, is to find a '91-92 transmission from a wrecker that has the
connection for the mechanical speedo and is currently hooked to a
blown 3.0L of which there should be a lot of in the wrecking yards.
Keep your existing transmission under the bench in your garage, and
put the wrecker one in and it will probably fail in 20-30K miles, right
around when the engine is going to be done.

Then you will have a core that has at least some of the upgrades and
you can take both blown transmissions to a rebuilder who can tear
both of them down and probably find enough hard parts that are
salvagable between both transmissions that they won't have to go
out and buy gearing or some such, which will drive up the price of the
rebuild. At the same time you can get the engine rebuilt. What you
will end up with is a $5,000 bill that will buy you a warranteed
powertrain that will probably last another 150K miles.

Whether such a thing is worth putting in your existing 89 body is
an entirely different issue. First question is, do you need a minivan?
They are handy things to be sure and I have found I like driving them,
but if you don't have kids, or your kids are grown, that removes a lot
of the incentive to have one. Second question is, just how good is
the body? Is there peeling paint? Is the paint still glossy? Is there
rust? Has it ever been in an accident?

Here in the Pacific NW it is quite possible to get a specimen
that has always been garaged, and driven by the proverbial
little old lady, which looks like it rolled off the assembly line
6 months ago. It's not common, though, but it's possible. It is,
in my opinion, quite justifyable to do a complete powertrain
rebuild on something like that, people do them all the time.

Ted

 

Wow, you've put a lot of thought into this. And wow, they sure did a
lot of work on that transmission design in just a year or two. Thanks
for the tip on getting the 91/92 transmission.

The particulars on my van are: 89 grand voyager, overdrive, loaded with
power options, leather seats, etc. Everything works great except the
transmission, which is in fact the overdrive model. I'd have to run
outside and look to be certain, but I'm pretty sure it has around 150k
miles on it. I bought it at the auction about 8 months ago for $450.
(I saw a 1990 that looks like its twin go at auction last week for $450,
so no shortage around here.) The body is impeccable, assuming that you
like white with fake wood, which I don't particularly. The 3.0L engine
runs beautifully with no smoke. The underside is so clean you could eat
your lunch off it, if the van happened to roll over. I have replaced
the shocks and struts, power steering pump, fuel filter, master cylinder
and two rear brake cylinders, as well as the pads and shoes of course.
My total investment is around $650, and I put around 20,000 miles on it
already myself delivering X-rays before my wife started driving it. We
have two kids, and we like throwing bikes in the back once in a while
for a family outing. The Dodge minivan is the most practical vehicle in
history, I think. Too bad the transmissions are problematic.

I drove a 1988 powertrain installed in a 1990 van to 275,000 miles a few
years ago, and my instinct tells me that my current van would be good
for a good long time to come if I were to fix it. Although there seems
to be a limitless stream of these things coming through the auctions I
hate to junk this one, because it's such a great specimen. It is
Chrysler minivan #12 for me, and it's the cleanest one yet, with the
most working equipment. Obviously it would be a good one to fix, rather
than selling it off. The question is whether I want to get 150 bucks
out of it and spend another $400 to $500 on a different van or bite the
bullet and spend all day saturday crawling around on the driveway
heaving a transmission around. For the past 5 years or so I've been
able to just about break even on cars. The only thing that costs me
money is minor maintenance and gas. I've already made $800 on one van
and lost $100 on another this year. I'll just have to decide whether
it's worth the effort to save a couple hundred and keep my average up.

 

Thats about how much longer it should have stayed in R&D instead of
being rushed into production in '89 :-/

And people say the age of miracles has ended! The 3.0 bottom-end is
actually reasonably reliable though not in the same league as the
Chrysler-built engines, and it will go a remarkably long time on a
timing belt too. The top end was the problem area, and if this one isn't
smoking then its almost certainly been through the mill of valve guide
fixes.

The later ones aren't, nor are the Chrysler-built 3.3 and 3.8 engines.

Reparing (if done right with all the best combination of parts) is
almost always more cost effective than selling a non-running vehicle and
buying another used one with another set of unknown problems.

 

If I were you I'd fix it. The reason is that in my opinion, while
there's
tons of these vans on the used market in the under-$300 range, just
about
all of them have transmission trouble. They are vans that are either
lightly driven with the factory transmission that has blown chunks,
or they are more heavily driven with at least 1 rebuild already done
on the transmission. Keep in mind that there's a lot of transmission
rebuild places that don't know what they are doing with these, still.

The companies that sell "rebuild kits" these days, which many
transmission
shops use, include all the updated parts and instructions on how to
retrofit them in. However, about 8-10 years ago, these companies
simply didn't know enough about mods that this transmission
needs to make it solid. For example, there are still places putting in
the
light-duty 9 inch converter into rebuilds - this is crap, the 10 inch
converter
is what you want. That is why there's so much stuff out there that
is in great shape except for a blown tranny.

If you unload this
one and buy another, you have a good chance of getting a transmission
that lasts maybe 10K and blows up again. Also, another used one your
going
to have to probably replace all over again all the piddly stuff like
the
struts/brakes/etc. etc. Since you have already dumped in the money on
that stuff if you fix this one you won't have to do it again.

If your thinking of doing the R&R yourself, you should take a look
at the writeup I did on mine when I did it this summer, it's here:

http://www.freebsd-corp-net-guide.com/94tcpics/project.html

You can R&R the transmission in a driveway if you have the right tools,
I did.

Ted

 

Yeah, I did it before on a 93 van. It's not hard to do, just tedious.
The great news is that my wife is encouraging me to fix it so we can
work on it together. I know a lot of folks would say that's a bad
thing, but not for us. It will be fun.

I'll be looking for the 91/92 transmission as you suggested. What code
numbers am I looking for on the bottom of the case?

 

Most transmission rebuilders scratch out the codes so I am not sure how
well this
will help, but here's what is in my 41TE/AE book:

First, look at your existing one, there's 2 possibilities:

1989 4446 659
1989 1/2 4531 664 both are Overall Top Gear Ratio of 2.36:1

The better one to have is the 1989 1/2

The production numbers for the transmissions that should cross are:

1990: 4531 551 OTGR 2.36:1
1990 1/4 4531 681 OTGR 2.36:1

1991 4567 848 OTGR 2.52:1
1992 4659 360 OTGR 2.52:1

1991 was when they put the newer transfer gears with the different
helix
angle those are more durable. 1991 also got the new spline converter
and the internal bypass valve and the new valve body. This is probably
the best year to look for.

1992 and later used the CCD Bus trans computer, a 1992 trans computer
from a wrecker will not work in yours although the 92 trans itself
should.

Note on the computers: if your computer is not a 4796121, it is a
factory original; REPLACE IT. Find a 4796121 in a yard. When you
do this you have to cut wire "cavity 49" of the TCM harness, this is
per TSB 18-24-95

Now, you may see Chrysler rebuilt/service replacements, those
numbers are:

1989 4531 687 or R4713 052 Note on this is "used 89 TR
(Transmission Range?) & PN
(Park Neutral?) Switches", I suspect a different year will have these
located in a different
place or perhaps a different connector?

Take lots of digital pictures of your existing transmission before
going out to the
wreckers.

Most of these vans have been through at least 1 trans rebuild, and
since the rebuilders
modify internal parts, they will scratch out the original service
numbers on the
transmission.