95 Caravan Transmission Problems

My 1995 transmission was overhauled about 5 years ago.

It started slipping this past week-end. I drove it today and couldn't
get it into high gear. Stayed at about 4500 rpm and 60 mph on the
freeway.

Do you think if I changed the fluid and filter it would help or am I
sunk?

I remember hearing about how some switch is thrown and the computer
won't let it continue shifting after there is a slippage?

Any recommendations?

Mike

 

When was the last time the tranny filter andf fluid was changed???

 

It was overhauled about 4 1/2 years ago. It hasn't been changed since
and never have had to add any.

 

That is the problem.

 

so i am up the river without a paddle? Too late to help it?

 

Get the trans computer code read to see what the problem is ... could be a
simple sensor that has failed. Do not drive it far in 2nd gear as you risk
major damage.

Bob

 

Bob,

How do I get that. Is that by turning the key on 3 times with the
mileage indicator pushed in? That is how I got the o2 sensor failure.

Mike

 

No. While a fluid flush and filter change is definitely overdue, most
likely
the fault is elsewhere. You need to take it to either a dealer, or a
transmission
shop and get it scanned.

ANY time that the transmission goes into "limp" mode (which is what yours
is doing) a code is set in the transmission computer that any garage with a
decent scantool (and by decent I don't mean the $199 pieces of shit that
they sell in the auto parts store) can retrieve.

"Limp mode" is documented in your owners manual. Basically the trans
computer when it senses a fault, will lock the trans in second gear. The
fault can be minor - such as a failed speed sensor - or it could be major,
like the transmission just fell out of the vehicle. The idea is to let you
get
to a garage. It is NOT to let you drive for a month on the freeway at
4500 rpm!

Incidentally, stay away from the chain store transmission shops. Find a
local small business trans repair shop that has done a LOT of these
transmissions. A very quick test when calling around to transmission
shops to find out who knows their heads from their asses is to tell
them you have a Chrysler vehicle, and ask them what kind of transmission
fluid they would use to refill it. If the answer is anything other than
either ATF +3 or ATF +4, hang up. If the answer is "Dexron plus
a friction modifier called Lubeguard" then not only hang up but tell
all your friends with Chryslers to stay away from them.

And when you do take it in for a flush, insist on seeing the drum of
ATF +3 or ATF +4 that they are going to use.

By the way, a not-infrequent failure in these transmissions is the
vehicle speed sensor, which is about a $30 part that takes about
20 minutes to remove and replace.

Ted

 

Good points.

Are you saying that I can not get the code myself? I got the code to
replace the O2 sensor, and fixed it. Would it not be there?

If it were the speed sensor and it was replaced, does the computer
reset itself when it sees a new one in there?

Mike

 

Mike,
Yes, no and yes in that order to your questions below. The key on-off-on
three times is the engine computer....you need to go to someone who can read
the transmission computer.
Bob

 

Thanks Bob

 

Agreed -- change the fluid and filter, using a genuine Chrysler filter,
genuine Chrysler fluid and genuine Chrysler gasket.

 

No, the 3-key-flick thing is for ENGINE codes only, and you don't have to
have the mileage indicator pushed in to do it.

The transmission supplies diagnostic information only through a diagnostic
computer hookup. Find a competent trans tech.

 

Next time how often should I change it (fluid and filter)?

Tomorrow I'm getting it hooked up for the diagnostic to find the codes
for $36. Reasonable?

I'll let you all know how it goes.

Mike

 

Yes, *if* the diagnostician is competent and honest.

 

I agree with Dan. Even better if he applies the diagnostic fee toward the
price of the repair. Good luck. Hope it is a simple input speed sensor.
(If it were the output sensor you would have lost your speedometer.)

Bob

 

The general recommendation is to use the severe duty schedule. That means
if your running ATF +3 every 15,000 miles. If your running ATF +4 I believe
that
they are 30,000 miles. ATF +4 is synthetic.

Your transmission was rebuilt after ATF +4 came on the market so the
clutch material and seals used should certainly have been compatible with
ATF +4.

ATF +4 isn't available in the aftermarket and is more than twice the cost
of ATF +3 or was, last I checked. However it is SUPPOSED to be
available in the aftermarket Real Soon Now. ATF +3 has been available
in the aftermarket for some years now.

Ted

 

Well I have the results of the codes. I think it is not good. Here they
are:

36 Fault Immediately after a shift
54 Gear Ratio Error in 4th
38 LockUp Control

LR Clutch CVI 60
2-4 Clutch CVI 59
OD Clutch CVI 102
UD Clutch CVI 53

What do you guys think?

MIke

 

The guy reset the computer and after I start the car I pushed the O/D
button so it does not go into 4th on the way home Looks like a problem
there.

Mike

 

CVIs are all within spec.

code 36 and 54 are a pair, 36 will never appear without another code. 54 is
being set because
the input speed sensor is telling the trans computer 1 RPM and the output
speed sensor is
telling the trans computer another RPM and the ratio between them is not in
the table of
gear ratios that the trans computer knows about.

According to the manual, more often the cause is a slipping OD clutch. Your
CVI for the OD
clutch is within range so this isn't being caused by clutch wear, it's
probably being caused by fluid pressure
problems, although there are other internal failures that can happen that
could cause this.

It might be possible a fluid flush and filter change would fix this. But
that is only a possibility.
If you pulled the pan and the filter was clogged with gunk that might be it.
But it shouldn't
be clogged with gunk, not on a 5 year old rebuild.

How many miles are on this rebuild?

My suspicions are on the rebuild itself. For starters, it really doesen't
bode well that
you wern't aware of the scheduled fluid change intervals - a competent
rebuild shop
should have made sure of this before you left. Also particularly with your
specific trans,
a rebuilder should have implemented TSB 21-15-95, changing the plastic
accumulator to
an aluminum one - if the manufacture date on the trans was between 9/1/94
and 7/14/95 -
because this is listed as a cause of this code. Do you know if yours did?

Also you have the code 38 which indicates other trouble that could be
unrelated - or
not.

Also, did your rebuilder replace the selonoid body or is it on the original
one
that came with the transmission?

Faced with a choice between a fluid flush and dropping the money into a
rebuild
you are pretty much going to be forced into trying the fluid flush I think -
but
just don't get upset if it doesen't work. If it was my van I would
absolutely
try the flush and replace the filter - but of course, if it failed I'd only
be out
the money for the filter and fluid, since I would be doing my own labor.

If you are mechanically able, you can do this yourself as well. Allpar has
a good description of the process.

Ted