[ShadMan]

I am having a problem with my wife's '94 JGC Laredo, 4.0L 6-cyl 4x4. At around 57mph it downshifts from OD, then upshifts again at about 63mph. It also downshifts when slowing down when it hits 57mph, then upshifts again to OD around 53mph. Something is triggering it around 57mph to downshift, whether speeding up or slowing down. I replaced the transmission output speed sensor on the rear of the transfer case yesterday thinking that would be the problem. They have a history of failing in this model vehicle, and cause shifting problems (No 1st, 4th, or OD gears, etc.). Well, that $50 did nothing for this problem, though I do have a new speed sensor that I won't have to worry about for a while!

I also noticed that the transfer case was low on fluid, so I drained and filled it.

Anyone have any other ideas? I just recently purchased this vehicle, and it was fine for a month or two before this problem started. One thing I noticed is that the transmission fluid appears to be a bit overfilled, but not much. Could that cause an issue like this? BTW, The fluid appears to be fairly new and clean.

Also, is it possible to make an adjustment on the tranny somehow to make it shift down sooner? When going around 30 or so in 4th gear, if you floor it, it'll drop to 3rd at (just guessing here) around 2000 RPMs give or take, but won't drop into 2nd. It seems like it should drop into 2nd at this speed when floored rather than 3rd. Is there a way to adjust this?

Just FYI, the tranny shifts firm but smooth in every gear and seems to be in great condition mechanically. The problems I am having appear to me to be electronic, but I'm not sure specifically which electronic devices could cause these problems.

Does anyone know where (if it becomes necessary) I can get a good price on a transmission control module/unit (TCM/TCU), 3/4 shift solenoid, and/or a throttle position sensor (TPS) and how much they run?

Thanks in advance!

[gregmondro]

i also need a tcu, any replies to this thread would be very useful

ttt

Originally Posted by ShadMan

I am having a problem with my wife's '94 JGC Laredo, 4.0L 6-cyl 4x4. At around 57mph it downshifts from OD, then upshifts again at about 63mph. It also downshifts when slowing down when it hits 57mph, then upshifts again to OD around 53mph. Something is triggering it around 57mph to downshift, whether speeding up or slowing down. I replaced the transmission output speed sensor on the rear of the transfer case yesterday thinking that would be the problem. They have a history of failing in this model vehicle, and cause shifting problems (No 1st, 4th, or OD gears, etc.). Well, that $50 did nothing for this problem, though I do have a new speed sensor that I won't have to worry about for a while!

I also noticed that the transfer case was low on fluid, so I drained and filled it.

Anyone have any other ideas? I just recently purchased this vehicle, and it was fine for a month or two before this problem started. One thing I noticed is that the transmission fluid appears to be a bit overfilled, but not much. Could that cause an issue like this? BTW, The fluid appears to be fairly new and clean.

Also, is it possible to make an adjustment on the tranny somehow to make it shift down sooner? When going around 30 or so in 4th gear, if you floor it, it'll drop to 3rd at (just guessing here) around 2000 RPMs give or take, but won't drop into 2nd. It seems like it should drop into 2nd at this speed when floored rather than 3rd. Is there a way to adjust this?

Just FYI, the tranny shifts firm but smooth in every gear and seems to be in great condition mechanically. The problems I am having appear to me to be electronic, but I'm not sure specifically which electronic devices could cause these problems.

Does anyone know where (if it becomes necessary) I can get a good prince on a transmission control module/unit (TCM/TCU), 3/4 shift solenoid, and/or a throttle position sensor (TPS) and how much they run?

Thanks in advance!

[ShadMan]

Just an FYI....my local dealer has these parts for:

3/4 shift solenoid $114.49
TCM $168.96
TPS $120.84

All of these include tax. Anyone know of better prices anywhere?

[greasefingers]

You may not want to guess because the parts are too expensive. Take it to a reputable place and have it diagnosed. My 1994 tranny was shot at 150K miles. It would rev to 3000 rpms in 1st, 2nd, & 3rd. I don’t know much about tranny’s, so I followed the Stealers advice and had it rebuilt. Hope yours is not so tragic.

[ShadMan]

FYI - I found the TPS online for around $65. I plan to test it this weekend with the multitester. Anyone have any other ideas what might be wrong. I really don't want to take it to the shop because I don't think it is mechanical. The fact that it happens at 57mph EVERY time, and ONLY at that speed leads me to believe it is electonic.

[ShadMan]

Well, I discovered that the sensor I replaced the first time was actually the Vehicle Spped Sensor (VSS) and not the Output Speed Sensor (OSS). I dropped the pan, changed the filter, replaced the OSS, added a few quarts of ATF+3, then flushed the tranny by disconnecting the transmission return line and draining into a bucket while adding new ATF+3 fluid until I noticed a difference in the color of the fluid. I wanted to make sure I completely drained the old fluid out (including torque converter, cooler, etc.) in case the previous owner had used Dexron/Mercron III. Filled to the proper level and test drove. No more erradic shifting!! I don't know if it was the fluid or the sensor, but I would definitely lean toward the sensor. $50 including fluid, filter, sensor, gasket. Sweet!

I was so excited I went ahead and replaced the front rotors and pads! Tomorrow will be fluid drain/fill on the differentials, checking motor compression, changing spark plugs, andmaybe flushing coolant system if I get really bored!

Thanks for the help and suggestions. Upcoming projects are rear drum/disc swap, FIPK, headers (anyone know where I can get them cheap??), and maybe a lift (front-->rear coil spring swap), larger tires, and ring/pinion swap to 3.73 (or possibly 4.11). Keep the suggestions coming!

[dequity]

Hey buddy,

ThANKS FOR TAKING THE TIME TO COME BACK AND POST WHAT FIXED IT. mY 93 JUST STARTED DOING THIS.

mATT

[greasefingers]

Yea there is very little information about fixing trannys. Thanks for your input and good job

[ShadMan]

Originally Posted by dequity

Hey buddy,

ThANKS FOR TAKING THE TIME TO COME BACK AND POST WHAT FIXED IT. mY 93 JUST STARTED DOING THIS.

mATT

No problem! Good luck!

[zjay]

Atf+3 should be fine, that's what the trans was designed to use. But to future fluid changers:


SUBJECT:
Automatic Transmission Fluid Usage ATF+4 (Type 9602)
MODELS:
1989 - 1995 (AA) Spirit/Acclaim/Lebaron Sedan
1989 - 2003 (AB) Ram Van/Wagon
1989 - 1993 (AC) Dynasty/New Yorker/New Yorker Salon
1989 - 1993 (AD) Ram Truck
1989 - 1994 (AG) Daytona
1989 (AH) Lancer/Lebaron GTS
1989 - 1995 (AJ) Lebaron Coupe/Lebaron Convertible
1989 - 1990 (AK) Aries/Reliant
1989 - 1990 (AL) Horizon/Omni
1989 (AM) Diplomat/Gran Fury/New Yorker fifth Avenue
1989 - 2004 (AN) Dakota
1989 - 1994 (AP) Shadow/Sundance
1990 - 1991 (AQ) Maserati
1990 - 1993 (AY) Imperial/New Yorker Fifth Avenue
1994 - 2003 (BR/BE) Ram Truck
2004 - 2005 (CS) Pacifica
1998 - 2003 (DN) Durango
2002 - 2004 (DR) Ram Truck
1995 - 2000 (FJ) Sebring/Avenger/Talon
2000 (GS) Chrysler Voyager (International Market)
2004 (HB) Durango
1995 - 2000 (JA) Cirrus/Stratus/Breeze
2001- 2004 (JR) Sebring Sedan & Convertible/Stratus Sedan
21-004-04 -2-
1996 - 2000 (JX) Sebring Convertible
2002 - 2004 (KJ) Liberty
1993 - 2004 (LH) Concorde/Intrepid/Vision/LHS/New
Yorker /300M
2005 (LX) Chrysler 300/Magnum
2000 (NS) Town & Country/Caravan/Voyager
1995 - 2004 (PL) Neon
2002 - 2003 (PG) PT Cruiser (International Markets)
2001 - 2005 (PT) PT Cruiser
1997 - 2002 (PR) Prowler
2001 - 2005 (RG) Chrysler Voyager (International Markets)
2001 - 2005 (RS) Town & Country/Caravan/Voyager
1997 - 2004 (TJ) Wrangler
2001 - 2004 (WG) Grand Cherokee (International Markets)
1999 - 2004 (WJ) Grand Cherokee
1989 - 1995 (YJ) Wrangler
1996 - 1998 (ZG) Grand Cherokee (International Markets)
1994 - 1998 (ZJ) Grand Cherokee/Grand Wagoneer

NOTE: This bulletin applies to all transmissions manufactured by Chrysler except for
1999 and earlier minivans with the 41TE/AE transmission, This Service Bulletin DOES
NOT apply to all AW-4 transmissions, Sprinter transmissions, Crossfire transmissions
and WG bodies equipped with a W5J400 or NAG1 transmission (sales code DGJ).
DISCUSSION:
A new transmission fluid (ATF+4® - Type 9602) has been developed and is being
used as factory fill for all vehicles with Chrysler automatic transmissions.It is
recommended that all vehicles with Chrysler automatic transmissions EXCEPT
FOR THOSE LISTED ABOVE be serviced with ATF+4®..
NOTE: ATF+4® must always be used in vehicles that were originally filled with ATF+4®.
NOTE: Service intervals do not change. The service interval currently in
effect for a given vehicle should continue to be followed.
NOTE: ATF+4® is compatible with ATF+3 and ATF+2. ATF+4 can be used
to top off vehicles that currently have ATF+2 or ATF+3. Do not use ATF+2
or ATF+3 to top off vehicles that have ATF+4® fluid.
BENEFITS
•Better anti-wear properties
•Improved rust/corrosion prevention
•Controls oxidation
-3- 21-004-04
•Eliminates deposits
•Controls friction
•Retains anti-foaming properties
•Superior properties for low temperature operation
FLUID COLOR
Mopar ATF+4® is a World Class Fluid having exceptional durability. However, the red dye
used in ATF+4® is not permanent; as the fluid ages it may become darker or appear brown in
color. ATF+4® also has a unique odor that may change with age. With ATF+4® fluid, color
and odor are no longer indicators of fluid condition and do not support a fluid change.


Just wanted to pass it along since I read above there is a trans info shortage!!