Let's start this off by making it clear: this is not a real "How To" as I have now only been involved in this project once. There's a lot of "figure it out" in this. However I do want to document an NSG370 to 42RLE swap in case it will help someone else later (it also works in the reverse 
). I had a lot of help, which is good because this is a lot of work and isn't for the faint of heart. I'm not kidding - you get fully committed to this pretty early on.
I have to thank the easter bunny for all his help not only introducing me to my donor but also helping source parts and more knowledge, along with the others that helped work on it. Anyone active around the forum can probably guess who they are.
We had an ideal scenario, two 2006 LJRs side by side. I don't really see another way beyond finding a very similarly equipped vehicle to have side by side unless you collect parts for a long time (and even then...)
Note: Headings that list a specific transmission mean the vehicle that will be LEAVING as that type. e.g. if you see "Automatic" that's the vehicle that will leave as an auto.
* New Flexplate Bolts
* Auto Radiator - do this ahead of time to limit active projects.
* Pilot Bearing Bushing (you can likely reuse what you pull out)
* New Flywheel Bolts
* Optional: Clutch, Throwout Bearing
* Optional: New trans tunnel cover
* Wire Loom (various sizes)
* Wire labels (I used zip ties with label tabs on them, but you can do whatever you'd like here such as masking tape).
* Transmission mounts. If you are both on the same skid, perfect. Otherwise - you might need to buy/build parts for the new trans if they're not in your old parts bin.
Here's an example of the Savvy auto (right) vs manual (left).
* Christmas tree zip ties
* Zip Ties
* Butt Splices/Wire repair things
* Blind bearing puller
* Plan a system of how you're going to organize parts. We had a big sheet of cardboard divided in half, one side each. Every bolt that came off went on it and into a labeled area.
Note that since you will have to swap all wiring in the engine bay and underneath - including the PDC, there's nothing special to look for here - unless one rig is a Rubicon and the other isn't, in which case - just stop now or accept the donor will lose their lockers + sensors unless they want to run the pump power directly (they'll lose the sensor lights in the cluster either way). We found that the rig without the fancy mirror also missed a temp sensor on the left side of the grille, but it did have the harness.
* Overdrive Switch Plug - this is a small white plug behind your toggle switches in the center bezel. I believe it's usually parked in the back of a blank.
Start at the PDC and remove/label all things it touches. It doesn't really matter if you know what a sensor is or does (though it helps if you have to reason about what's what later). You just need to be consistent in your labeling across each rig being sure to label both the male and female end of the connectors. Same as below: this is a good time to walk the harness and check for any excessive chaffing, wear, etc. Fix it now because you won't have as easy access again.
Note the two connectors with a grommet just left of them about 1/3 the way down on each harness (between the feet). Those two big connectors feed through the firewall by the brake pedal and connect to the in-cab wiring you won't really need to touch.
Once it's pulled would be a good time to trace the harness and make sure it's still healthy. We found multiple spots in both harnesses that could use some love with repair/patching/reinforcing/looming.
Your engine bay will never look so clean again.
* Pilot Bearing Bushing
* Clutch Master/Slave
* Firewall plug (on the firewall above the trans tunnel on the driver side)
* Pedals (brake + clutch) - be sure to watch out for the brake light sensor and clutch interlock connector
* Steering Column Housing
* Ignition Cylinder (KEEP THIS WITH YOUR RIG)
* Ignition Cylinder interlock (the little switch behind the key that lets it turn to off)
* Transmission tunnel cover
* Shifter + boot (use a T45 to remove the shifter from the transmission, don't ever lose or throw away the ring around the boot)
* Starter
* Overdrive switch
* Transmission Cooler Lines
* Pedals
* Steering Column Housing
* Ignition Cylinder (KEEP THIS WITH YOUR RIG)
* Ignition Cylinder Interlock (this is a cable that goes to the automatic shifter). BE CAREFUL: There is a small sliver in this that would be easy to lose. It won't jump out, but it could fall out - so just watch for it and be careful.
* Transmission Shifter (this routes through the firewall at the top of the transmission tunnel)
* Clutch Master Firewall Cover
* Transmission tunnel cover/Auto Shifter Bracket
* Starter
* Dipstick
For the internal pieces we swapped we just did those one at a time, but find whatever way works for you.
* The starters swap.
* You will need to adjust your brake light sensor after the pedals swap. To do this, simply depress your brake pedal and use some pliers to move the sensor shaft out, letting the brake pedal self adjust. The sensor is facing the top of the brake pedal's arm on the bracket. See here if you want a video.
* Rubicons disable the clutch interlock (inability to start the rig without the clutch being depressed) in 4low. Don't test that functionality (if you care about it) in 4low.
* This took us about 2.5 days of work.
* PCM: Get your PCM reprogrammed for your VIN, you can do this at WranglerFix. This is important for emissions things (if applicable), and probably others.
* SKIM: Address SKIM things, maybe WranglerFix can help?
* If you now have an auto: get a trans cooler and a temperature sensor installed.
* There may be surprises in store, just be ready to address them.
Again: we had a pretty lucky and ideal scenario. Both rigs had the wiring they needed inside, they also had most the same features. Do not underestimate the differences you could see that I didn't. Do your homework.
). I had a lot of help, which is good because this is a lot of work and isn't for the faint of heart. I'm not kidding - you get fully committed to this pretty early on.I have to thank the easter bunny for all his help not only introducing me to my donor but also helping source parts and more knowledge, along with the others that helped work on it. Anyone active around the forum can probably guess who they are.
We had an ideal scenario, two 2006 LJRs side by side. I don't really see another way beyond finding a very similarly equipped vehicle to have side by side unless you collect parts for a long time (and even then...)
Note: Headings that list a specific transmission mean the vehicle that will be LEAVING as that type. e.g. if you see "Automatic" that's the vehicle that will leave as an auto.
Prerequisites
Be prepared! There's a lot of random things you might need. These are non-exhaustive lists for the end-result vehicle.Automatic
* New Crank Bushing* New Flexplate Bolts
* Auto Radiator - do this ahead of time to limit active projects.
Manual
* Pilot Bearing* Pilot Bearing Bushing (you can likely reuse what you pull out)
* New Flywheel Bolts
* Optional: Clutch, Throwout Bearing
* Optional: New trans tunnel cover
Misc
* A few rolls of electrical tape* Wire Loom (various sizes)
* Wire labels (I used zip ties with label tabs on them, but you can do whatever you'd like here such as masking tape).
* Transmission mounts. If you are both on the same skid, perfect. Otherwise - you might need to buy/build parts for the new trans if they're not in your old parts bin.
Here's an example of the Savvy auto (right) vs manual (left).
* Christmas tree zip ties
* Zip Ties
* Butt Splices/Wire repair things
* Blind bearing puller
* Plan a system of how you're going to organize parts. We had a big sheet of cardboard divided in half, one side each. Every bolt that came off went on it and into a labeled area.
Let's talk SKIM
All I can say here is one of us had SKIM enabled and one did not. I was able to have wranglerfix.com disable my SKIM. When I sent the PCM out to get that disabled I pulled the SKIM plug out, so I could drive around when it got back until the swap. It went into the other vehicle with no issue. Similarly since he didn't ever have SKIM his went into mine fine. I believe it is more complicated if both parties already have SKIM, but am not familiar enough to speak intelligently to that.What wiring should I check for beforehand?
05/06 Jeeps are fairly annoying here and two rigs of the same year may not have everything the same due to available options. It doesn't make sense why, but it's what those with more experience have told me. So here's some things to check for.Note that since you will have to swap all wiring in the engine bay and underneath - including the PDC, there's nothing special to look for here - unless one rig is a Rubicon and the other isn't, in which case - just stop now or accept the donor will lose their lockers + sensors unless they want to run the pump power directly (they'll lose the sensor lights in the cluster either way). We found that the rig without the fancy mirror also missed a temp sensor on the left side of the grille, but it did have the harness.
Automatic
* Shifter bezel light socket (not really important)* Overdrive Switch Plug - this is a small white plug behind your toggle switches in the center bezel. I believe it's usually parked in the back of a blank.
Manual
* Clutch Interlock (small black plug with a maroon wire housing above the ODBII)Still have the stomach for it?
You get into the thick of it rather quickly. Just check yourself one more time that both parties are ready to commit and go. It's incredibly involved as you will remove every external connector on each rig.Drop Gas Tanks
A very unfortunate thing of the late models is that they do not have accessible wiring disconnects. As such, you can either choose to add a pigtail now or drop your tank to access the top of the fuel pump to remove this connector.Disconnect Batteries
Disconnect the batteries and pull the PCMs.Remove Transmissions
If you can't pull your transmission, turn back. Label anything you disconnect as you go. Seriously, it's easy to remember a couple connections, but soon enough you will be deep into connectors you aren't going to want to have to reason about.Pull and label the engine bay wiring harness
Take a bunch of pictures of how things sit now, even if you're not sure what you need. Just get a bunch of overviews from different angles and closer shots on busier areas.Start at the PDC and remove/label all things it touches. It doesn't really matter if you know what a sensor is or does (though it helps if you have to reason about what's what later). You just need to be consistent in your labeling across each rig being sure to label both the male and female end of the connectors. Same as below: this is a good time to walk the harness and check for any excessive chaffing, wear, etc. Fix it now because you won't have as easy access again.
Note the two connectors with a grommet just left of them about 1/3 the way down on each harness (between the feet). Those two big connectors feed through the firewall by the brake pedal and connect to the in-cab wiring you won't really need to touch.
Pull and label the rest of the wiring
I started at the gas tank and worked forward connector by connector. Again, label both sides and be consistent (where you can) between the auto and the manual. Obviously the auto will have a bunch of extra sensors in the middle.Once it's pulled would be a good time to trace the harness and make sure it's still healthy. We found multiple spots in both harnesses that could use some love with repair/patching/reinforcing/looming.
Your engine bay will never look so clean again.
Remove things from the was-a-manual
* Pilot Bearing* Pilot Bearing Bushing
* Clutch Master/Slave
* Firewall plug (on the firewall above the trans tunnel on the driver side)
* Pedals (brake + clutch) - be sure to watch out for the brake light sensor and clutch interlock connector
* Steering Column Housing
* Ignition Cylinder (KEEP THIS WITH YOUR RIG)
* Ignition Cylinder interlock (the little switch behind the key that lets it turn to off)
* Transmission tunnel cover
* Shifter + boot (use a T45 to remove the shifter from the transmission, don't ever lose or throw away the ring around the boot)
* Starter
Remove things from the was-an-auto
* Crank Bushing - this is known to be very tough so you will likely need to get creative. Do not damage the crank.* Overdrive switch
* Transmission Cooler Lines
* Pedals
* Steering Column Housing
* Ignition Cylinder (KEEP THIS WITH YOUR RIG)
* Ignition Cylinder Interlock (this is a cable that goes to the automatic shifter). BE CAREFUL: There is a small sliver in this that would be easy to lose. It won't jump out, but it could fall out - so just watch for it and be careful.
* Transmission Shifter (this routes through the firewall at the top of the transmission tunnel)
* Clutch Master Firewall Cover
* Transmission tunnel cover/Auto Shifter Bracket
* Starter
* Dipstick
Put it all back together on the other rig.
That title is a bit short, but this is pretty much what you do. I started at the manifold connectors and worked back slowly, trying to not twist the harness as I went.For the internal pieces we swapped we just did those one at a time, but find whatever way works for you.
Notes:
* Some bolts move over with the transmission. Pretty much any bolts that touch the transmission will move, aside from your transfer case nuts. That includes bell housing bolts and starter bolts.* The starters swap.
* You will need to adjust your brake light sensor after the pedals swap. To do this, simply depress your brake pedal and use some pliers to move the sensor shaft out, letting the brake pedal self adjust. The sensor is facing the top of the brake pedal's arm on the bracket. See here if you want a video.
* Rubicons disable the clutch interlock (inability to start the rig without the clutch being depressed) in 4low. Don't test that functionality (if you care about it) in 4low.
* This took us about 2.5 days of work.
Follow Ups
Once you're done, you're not really done. Afterward you'll want to get your PCM programmed to your body's VIN. WranglerFix can help you here. If you want to maintain SKIM you may also need to talk to Mark* PCM: Get your PCM reprogrammed for your VIN, you can do this at WranglerFix. This is important for emissions things (if applicable), and probably others.
* SKIM: Address SKIM things, maybe WranglerFix can help?
* If you now have an auto: get a trans cooler and a temperature sensor installed.
* There may be surprises in store, just be ready to address them.
Again: we had a pretty lucky and ideal scenario. Both rigs had the wiring they needed inside, they also had most the same features. Do not underestimate the differences you could see that I didn't. Do your homework.
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