1989 Jeep YJ Wrangler 904/999 Torqueflite Troubles

[Neutel]

Hi

im from the Netherlands,. (So sorry for my bad English) and got a problem with a 89 jeep wrangler

The jeep gots a 4,2 6cilinder with I guess a 32rh transmission

the transmission pump has eating the converter ;)

so the converter was rebuild, en a another pump mount, but I've changes also the clutch plates and seals

after a

everything was assembled :

the car drives 1&2 gears perfect but the 3rd gear late, and. Cold very late. The reverse was slipping,

so I've put everything out (again) and checks the front clutch, I've thought the inner seal of the front clutch was not right,

after a new seal, and everything together

the reverse works great!

but still the 3rd gear is late and sometimes gone...

ive tried another valve body, but doesn't help anything

well did I see the rear band is going worn???

and went I put the front clutch on the pump and do a air check with 30psi the air is leaking between pump reaction shaft and the clutch housing

but the front clutch sealing rings are new

 

short:

why does my rearband and rear drum go worn

why does the 3rd gear shift so late/ is it usually that it leaks between reaction shaft and clutch by 30 psi?

 

thanks

 

Bas

[Moses Ludel]

Neutel...Welcome to the forums!  

Your 1989 Jeep YJ Wrangler has a Chrysler 999 transmission, the mechanical version not the later electronically controlled 32RH.  The late shift to 3rd gear and slipping in reverse could be related.  Since the transmission is in the chassis, and you describe these troubles, I would check the port pressures accessible at the transmission case. 

I would begin by checking the port pressures, which you will find in the first PDF below.  This will determine what pressure is actually available at the front and rear servos and the governor circuit.  Each of these pressure values play an important role in making shifts, shift timing and band application.  You may have a fluid pressure issue and possible pressure problems at the bands and the governor.

Be aware that the accumulator is important to shifts and band apply pressures.  The 999 and other rear wheel drive (RWD) Chrysler transmissions are notorious for poor accumulator sealing.  Sonnax has an upgrade accumulator and improved rear servo parts to overcome the weaknesses.  See my article on RWD Chrysler 999/727, RWD OD and RH/RE  transmissions: http://www.4wdmechanix.com/Survival-Upgrades-for-Jeep-and-Dodge-Ram-Automatic-Transmissions?r=1.  Also see this information at Sonnax regarding RWD Chrysler transmission problems:  http://www.sonnax.com/searches?utf8=✓&query=chrysler+RWD&commit=Go.

Here are the pressure tests for your 999 transmission in the vehicle.  You will need a fluid pressure gauge to run these tests.  Read the chart on the 3rd page of the PDF.  This shows the connection between the pressure tests and the internal problems within the transmission: 

YJ Wrangler 999 Pressure Checks.pdf

If you need to alter pressure, the pressure adjustment is at the pressure regulator valve on the valve body.  Vital adjustments include shift linkage, the throttle valve linkage and the kickdown settings.  Here is additional testing and checks plus another detailed troubleshooting chart:

Adjustments and Troubleshooting a YJ 999.pdf

Let us know what you find, we can go from there...

Moses

[Neutel]

Thanks Moses,

 

line pressure -> fine
rear servo pressure -> fine
front servo pressure -> 0!!!
that wil be almost sure, front clutch...
 

when the first time the converter and pump were broken, ive put a another pump in it,
but i found the pump isn't right!!
Ive have place the front clutch what belongs to this pump, and it works fine....

so i think ive looking for some parts.... or another automatic transmission

 

[Moses Ludel]

Neutel...Did you get the "0" reading at the front servo with the shifter in "D" position?  On Page #21-66 of the pressure testing PDF, in the first column under "Test Three-Transmission in D Range", note that the front servo is only pressurized with the shifter in "D" shifter range.  Mopar wants technicians to use two gauges for this test, one at the line pressure port, the other at the front servo.

Line pressure should be 54-60 psi (372-414 kPa) with the throttle lever moved all the way forward (maximum setting).  Pressure increases as the throttle lever moves rearward.  The test is performed with the engine at a constant 1600 rpm.  You move the throttle lever at the transmission, do not move the throttle/kickdown lever with the gas pedal.  Do not open the gas pedal; keep engine rpm at 1600 during this test.

The Jeep must be safely on a vehicle hoist or quality jack stands when performing this test.  Do not get hurt!...The throttle pressure should nearly match (within 3 psi or 21 kPa) the transmission line pressure during the test.  This throttle lever position is just before the "kickdown" position on the throttle lever.

Moses