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Transmission help after 2wd to 4wd swap

Well I didn’t get a chance to do the voltage test that was suggested for the output sensor so I will do that when I get a chance. I have an extra tps so I can swap that also just for the heck of it. I figure if all else fails I can swap all the solenoids and wires from the original 2wd over to this transmission and see what happens. That is just a lot of time I don’t have right now.


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Finally had a few hours to work on this. I swapped over every solenoid and wire from the original 2wd transmission that worked perfectly when I pulled it. Now all solenoids test good with the ohm meter and all wires as well.

No change

Next I swapped a new tps just to try it out even though the original one still had good smooth voltage. No change.

I now have all original wires and sensors and torque converter from the 2wd transmission in the 4wd. I can shift through 1,3,4,r manually with the fuse pulled but it just revs up and won’t shift with the fuse in.

So basically everything was working fine when I pulled the 2wd transmission and everything is now the exact same as pre swap with the exception of the transmission itself which shifts fine manually.


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Are you sure you have a good ground? Have you tried swapping in a known good TCU? Do you have a FSM for your year?
 
I forget but did you already try adjusting the throttle valve cable?
 
I'm wondering if the rear output speed sensor is working or not fully plugged in. It's the white connector on the first picture you posted. Unplug it and stick the meter on it set to ohms, or back probe at the connector or at the TCM plug while plugged in with meter set to voltage. It's a magnetic switch on that year, and you should see it change from zero ohms to open circuit if measuring it unplugged, or jumping between 0-12 volts if plugged in with the key-on, once per revolution.

To spin the output slowly to see it changing, stick the trans in neutral, jack a rear tire up and rotate it to see it. Or slowly let the vehicle roll. You could also stick the xfer case in neutral and the trans in drive, but that's a little harder to quantify with the meter as it'll look more like a/c voltage at that point. (side note: the 98+ puts out voltage pikes, so spinning it in drive is the better way to check those years)
 
The transmission in the picture is an 'early' transmission, w/o the input shaft speed sensor.

And I'd like to clarify a point that I made earlier, re, the folly of converting a 2WD to 4X4. I estimated that I could have saved $2500 by buying a 4X4 to start with. HAHAHA! That was before I got to the front axle assembly. I have several parts on my shop floor to remind me what a stupid plan this was, Including a splendid, freshly rebuilt AW4, a complete front axle, and several rotors 'n' hubs that track the changes that Chrysler made to the front end for reasons that elude me.
 
Ok so I checked all grounds and they appear solid and clean. Went to check the output sensor and I got 4.8 volts under all circumstances and open when testing ohms. I also pulled it out and put it in the old transmission and spun that one and there was no reading. So maybe this sensor is my problem. Seems strange that it worked perfect when I pulled the transmission and now it’s bad. Now I need to find that sensor and give it a try. And as far as swapping in a different tcm, I don’t have an extra laying around so that isn’t going to happen right now.


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Ok so I checked all grounds and they appear solid and clean. Went to check the output sensor and I got 4.8 volts under all circumstances and open when testing ohms. I also pulled it out and put it in the old transmission and spun that one and there was no reading. So maybe this sensor is my problem. Seems strange that it worked perfect when I pulled the transmission and now it’s bad. Now I need to find that sensor and give it a try. And as far as swapping in a different tcm, I don’t have an extra laying around so that isn’t going to happen right now.

Possible you damaged the wiring to it? Maybe pull back the loom and use a couple of pins through the wires closer to the sensor.

Its Mopar 83503722 or Crown 83503722, Standard Motor Products SC122 about $69. The part number is unique to Jeep even though it's a Toyota trans. I suspect there is a Toyota part number that might work, but it might may have a different connector or lack the extended wiring. The part number for the 98+ sensors (which are very different than the 95) look identical between Jeep and Toyota and it's $20.
 
Solved! Stupid mistake on my part. I had previously narrowed it down to the speed sensor in the tail housing. Upon deep contemplation I realized that it was nearly impossible that everything worked perfect before the swap but not after, so I was missing something. So... the speed sensor needs to read something to have a reading to send to the computer. I forgot to install the magnet in the tail housing when I reassembled everything. So I installed the magnet and now everything works perfect. Done. Thanks for the help everyone.


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