Transmission swap questions

n2jeepin

New Member
Joined
Jan 18, 2019
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Location
Manama, Bahrain
Good morning all! I hope someone can help me plan a swap. I have two 2006 Jeep TJs and I want to swap the transmission from one (US spec-Manual 6 Speed) to another (Export Spec-Automatic). I know this isn't common question here since I own both Jeeps, but I'm overseas and I can only bring the (US Spec) TJ back without spending a lot of money verifying that is meets all the US standards even though they were both made in the same factory in Toledo Ohio. My main concern is the wiring. I know I have to swap the PCM and steering columns due to on of them having a SKIM module. Which means I will need to swap all the door locks and tailgate also. I'm asking if you think I'll have to swap both complete wiring harness from both TJ's also? Or should I be able to just swap the Automatic control wiring from the PCM and the overdrive switch? Any suggests on how to tackle this project would be greatly appreciated. I really want the automatic in the TJ before I ship it back to the states. I have really enjoyed driving the automatic more than the stick due to traffic here on this island. Please let me know if anyone has any thoughts on the wiring or anywhere else I might run into issues with this swap.
 
Hi @n2jeepin

I did not know much about the US , Export specs much. I'm look into similar project few times. As far as my few notes, the SKIM part is not necessary to change. You can reprogram the SKIM to the new PCM. I does never does it but few members here have deal with this.

I will like to wait for the experts to weight in on the PCM and the automatic control wiring part. I still collecting info but still not have solid conclusions of what really is need to complete this task as the Auto to Shift transmission swap subject get rapidly derail by the fellas that are grasping to solve the 05-06 42RLE shifting issues difficulting the information gathering.
 
To my knowledge, it’s all one wiring harness. Meaning you can’t just swap the transmission wiring harness, as it’s part of main wiring harness.

It would be helpful to know what year the vehicles are as well.
 
Thanks for the quick reply. I'm actually going from the six-speed manual to the 42RLE. But I'm trying to see if almost all the wiring harnesses and power distro box needs to be swapped. I promised my wife a Jeep with an automatic but TJ that I can take back to the states aren't that common here. I found a local Export TJ with an automatic and bought it for a very good price since it wasn't running well and was throwing codes. But I have fix all the issue with the local Export TJ and now what to swap the transmission around and the axles. The export has a Dana 44 and the US Spec TJ had a Dana 35 with 3.07 gears (Never will I understand how Jeep used 3.07 gears in a Jeep). I have the Factory service manual and I see most of the wires that have to be attached to the Automatic but I don't believe my Manual harness will be wired for the fuses and other required connections for the 42RLE. I wish I could just swap a six-speed Automatic but I don't know of any company that makes adapters for a GM/Dodge six-speed automatic to Jeep 4.0L engine.
 
To my knowledge, it’s all one wiring harness. Meaning you can’t just swap the transmission wiring harness, as it’s part of main wiring harness.

It would be helpful to know what year the vehicles are as well.
Sorry about that. Both Jeeps are 2006's. US Spec in X model and the Export is a Sport
 
Sorry about that. Both Jeeps are 2006's. US Spec in X model and the Export is a Sport

Okay. On the 05-06 models with the 42RLE transmission, the TCM and ECM were combined into one module... the PCM. So the PCM on those 05-06 models controls the engine and transmission, whereas on the earlier models prior to 2005, they had a separate computer for both the engine and transmission (called the TCM and ECM).

Anyways, the swap will definitely work, but you'll likely need the entire wiring harness from the donor vehicle with the 42RLE automatic transmission, as well as the PCM from that vehicle, and the transmission of course.
 
Sorry about that. Both Jeeps are 2006's. US Spec in X model and the Export is a Sport
The Sport and X should be cross compatible.
You don't need to move the column over, just the module. The skim connector is there on both.
You will have to swap the under dash harness to get the OD switch moved over.
You will need to swap the under hood engine harness and trans harness on both due to how the NSS switch circuit is wired for the 6 speed and the auto harness for the 42.
If the tail lights look the same on both and you can verify the connectors are the same, the easy thing to do is cut the harness right behind the T-case to save dropping the fuel tank for that rear section of harness. You can open the loom and check wire color and count at the same spot.
The PDC should be the same. Try to leave them in place if possible. If fuses and relays are missing, just swap them between the two.
DO NOT power either up until the swaps are done to avoid activating the SKIM in the Non SKIM PCM. That will suck.
 
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The Sport and X should be cross compatible.
You don't need to move the column over, just the module. The skim connector is there on both.
You will have to swap the under dash harness to get the OD switch moved over.
You will need to swap the under hood engine harness and trans harness on both due to how the NSS switch circuit is wired for the 6 speed and the auto harness for the 42.
If the tail lights look the same on both and you can verify the connectors are the same, the easy thing to do is cut the harness right behind the T-case to save dropping the fuel tank for that rear section of harness. You can open the loom and check wire color and count at the same spot.
The PDC should be the same. Try to leave them in place if possible. If fuses and relays are missing, just swap them between the two.
DO NOT power either up until the swaps are done to avoid activating the SKIM in the Non SKIM PCM. That will suck.
Thank you for your advice. I was thinking I could just take out the C4 connector from the PCM but after looking in the engine bay it would be better to swap the whole harness. As for the Steering column, does the Ignition lock cable from the auto shifter will bolt up to the Manual steering column? I have read about the SKIM module, Once I start swapping harnesses I'll swap the skim module and PCMs first. Thank you again for all your advice,Now I know how big of a project this really is vice just swapping some transmissions and wires. Thank you!
 
Okay. On the 05-06 models with the 42RLE transmission, the TCM and ECM were combined into one module... the PCM. So the PCM on those 05-06 models controls the engine and transmission, whereas on the earlier models prior to 2005, they had a separate computer for both the engine and transmission (called the TCM and ECM).

Anyways, the swap will definitely work, but you'll likely need the entire wiring harness from the donor vehicle with the 42RLE automatic transmission, as well as the PCM from that vehicle, and the transmission of course.
Thank you for your advice. Both TJ's are fully operational and I hope they both will be after the swap. I was hoping to save some time not having to swap the complete harnesses. Know I have to hope I don't break any of the connectors while removing them. Thanks for all your advice and if anyone is interested how it turns out I can post my progress.
 
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Thanks for all your advice and if anyone is interested how it turns out I can post my progress.

You're welcome! Yes, definitely share your progress. I'm sure it will be of much help to other members in the future.
 
Thank you for your advice. I was thinking I could just take out the C4 connector from the PCM but after looking in the engine bay it would be better to swap the whole harness. As for the Steering column, does the Ignition lock cable from the auto shifter will bolt up to the Manual steering column? I have read about the SKIM module, Once I start swapping harnesses I'll swap the skim module and PCMs first. Thank you again for all your advice,Now I know how big of a project this really is vice just swapping some transmissions and wires. Thank you!
Yes, you can move the shifter lock cable and lock box from one to the other. When you open the little module under the column, there is a very small "chiclet" of pot metal that has to be oriented correctly to make the lock work as designed. Watch for it and don't lose it.

Thinking again about moving over the key release for the manual and the fact that you have both, it may be easier to go with your first thought which is to just swap columns. I focused on the wrong aspect which was the SKIM module which is not part of the column.
 
Thank you for your advice. Both TJ's are fully operational and I hope they both will be after the swap. I was hoping to save some time not having to swap the complete harnesses. Know I have to hope I don't break any of the connectors while removing them. Thanks for all your advice and if anyone is interested how it turns out I can post my progress.
Get a good air nozzle, squeeze the connectors together and blow the dust and dirt out of them. That helps them to release easier.
 
Yes, you can move the shifter lock cable and lock box from one to the other. When you open the little module under the column, there is a very small "chiclet" of pot metal that has to be oriented correctly to make the lock work as designed. Watch for it and don't lose it.

Thinking again about moving over the key release for the manual and the fact that you have both, it may be easier to go with your first thought which is to just swap columns. I focused on the wrong aspect which was the SKIM module which is not part of the column.
Thank you again Mr. Blaine! I will just swap the steering columns to make it simpler (I hope). Thank you again for all your help!
 
Get a good air nozzle, squeeze the connectors together and blow the dust and dirt out of them. That helps them to release easier.
Thanks again for this advice! I will do that since it is extremely dusty over here and being hit my a two day dust storm at this time. Thank you so much for all the help!!!
 
hell just swop the the vin tag and sticker in door jam and say FUCK THE GOVERNMENT
You can try that. The problem is the VIN is stored at least 3 other places and depending on how pissy the .gov wants to get about it, they can reject your application if they all don't match. Most, unlike myself, don't have a set of the special head shape and color rivets that hold the VIN plate to the dash and they look for that one first so it is not as easy to tell the .gov to piss off as one would think.
 
hell just swop the the vin tag and sticker in door jam and say FUCK THE GOVERNMENT
I wish it was that easy also. But they look for the emission sticker under the hood and VIN tags on the dash and door jamb. It just isn't worth fines or losing my TJ over and maybe my job since I work for the Government (Navy). But thanks for the suggestion, I have to admit I have thought of this option myself!
 
You can try that. The problem is the VIN is stored at least 3 other places and depending on how pissy the .gov wants to get about it, they can reject your application if they all don't match. Most, unlike myself, don't have a set of the special head shape and color rivets that hold the VIN plate to the dash and they look for that one first so it is not as easy to tell the .gov to piss off as one would think.
Mr. Blaine, thank you for your input again. That is the reasoning behind the swap. I did think about swapping out the complete dash and order a replacement Door jamb sticker. But the 2006 wrangler has the VIN on almost every part (assume to stop strip shops) and didn't want to risk any issue on it being shipped back. Better to put the hours in and swap the parts I need. Thank you again for all your help!