Questions for anyone who has done a 5.9 swap

Jeepsr4grls89

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I am new here. Looking for any advice from people who have done a 5.9 swap in to their TJ. I have a 1997 TJ with a 2.5, automatic transmission. I know I will basically have to gut the whole lower half of my Jeep. Will I be able to use my factory harness when it comes time since I have the 4cyl? Has anyone on here done this with a 4cyl before? Just looking for some advice before I start ripping in to it. Going to rebuild the 5.9 this winter and then hopefully start ripping in to my old girl this spring. I have had this Jeep since I was 16, so this build is special. I want to do it right.
 

pcoplin

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I installed a 5.9 in my 4 cylinder Jeep back in 2007. I had someone do my harness for me though. I ended up having to redo a lot of it.

I've done several Chevy ones, which are much easier. If I were to do it again, I would lay both out, study the schematics, and blend the two harness together. Take a lot of hours. There are several who have added the extra injectors to the TJ 4.0 harness, but I don't think the 2.5 harness is long enough for that. The Dodge harness is an engine-only harness, where the TJ harness is integrated through the dash and goes all the way back to the fuel tank. Not a super easy swap wiring-wise, but everything else is quite easy.
 
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Jamison C

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Check out @RangerRick's build thread on a 2.5 to 5.2 swap. It’s practically a 5.9 with a few minor differences.

I was gonna do this swap but opted for keeping the 4.0. Did hours of research on it though.

As far as the harness goes, it’s advised to “blend” the donor harness with the TJ harness. Use a 5.9 with a CCD bus ECM, same as your TJ. Best one would be a 5.9 out of a ‘98 Cherokee. The exhaust headers and Y pipe fit with no mods, the starter is on the passenger side just like the TJ, and it already has the narrower power steering bracket that will fit in your engine bay. Anything out of a Dakota, Ram, or Durango will be a little more challenging in the areas listed above.

There’s thread after thread on this info online, spend some time doing research, I’d be confident doing one on my own at this point.
 

RangerRick

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@Chris and @Jamison C are both spot on here on preliminary guidance here. As someone who has done the swap, I highly recommend starting with the ZJ Grand Cherokee V8 as a donor vehicle because of the passenger side starter and "y" pipe that can save you fabrication time. These are old cars now and many times need lots of work so you can pick the whole vehicle up for a very low buy-in price. There are countless parts that you can pick from the donor to help with your swap besides the obvious parts you'll need.

Keep in mind however the 5.2L engine is internally balanced vs. the 5.9L which is externally balanced so the flex plates for the transmissions must match the engine for which you plan to run or you'll have vibrations and possible bearing or seal failures down the road if you don't pay close attention to this detail.

Sounds like @Jeepsr4grls89 you already have a 5.9 L Magnum V8 you plan to rebuild. The wiring harnesses are 100% interchangeable between the 5,2 & 5,9. That's fine, replace all the gaskets including the infamous intake plenum plate, do the timing chain & sprockets and go through it before you drop it in making it easy to get to all parts of the engine while it's on a stand and you can turn it upside down, sideways, or whatever to work on it. All good!

As far as the harness is concerned, I recommend you look at my project build pages because I detail what reference shop manuals you should use and some of the wiring that I did. Unlike many who have done this swap I did ALL the wiring myself and used the ZJ engine side harness to blend with the TJ body harness for the end result. The portions of the TJ harness that I kept were the charging and alternator circuit wiring & plugs, the fuel pump and sender harness and it's related parts. The two plugs on the firewall that go to the TJ body harness were blended and added to the ZJ engine harness and I used the PDC (passenger fender fuse box) parts for both the ZJ & TJ. I re-used the TJ brackets and the fuse box parts but added the necessary TCR (Transmission Control Relay) to the PDC and it's protection fuse circuit.

My TJ was a very early one. It was built 3/1996 and didn't have anything for cruise control or security chip key etc. I added the cruise control wiring and it's related parts for fully functional cruise operation. Not hard since I was already doing the whole wire harness...

My TJ was already an automatic so it was easy to find a later 2003-2006 bezel and indicator for the overdrive feature of the 46RE transmission. I could have used the NP/NVG-231J transfer case that was connected to the 30RH in my TJ but decided to install and Atlas II since I was installing Currie Rock Jock 60's at the same time. It was a big project where I even changed all the interior out for that of a 2005 Rubicon. When I was at the bottom of the tear-down, it looked like a frame-off rebuild. This took 2 1/2 years to get most of it done ( I have 3 kids that were under 4 years old at the time) and I am still redoing the body and armor she wears now.

Again, there are many details on my "Redheaded Stepchild" build showing how the cooling system went together and what to use etc. Ask questions if you don't know, I specifically took the time to build my swap so it was like the factory would have done it. For the most part, all factory parts, no funky custom aftermarket anything with the exception of the motor mounts. I wanted it to look like I checked the V8 box when I ordered the Jeep new if you catch my drift. Even the fan shroud is from a 4.0L TJ and the fan is a stock 5.2L ZJ unit so if anything should fail, any dealership or parts house will have what's needed for the repairs.....

Speaking of parts & donors:
I have a 1998 ZJ Grand Cherokee potential Engine/Transmission & parts donor I will be parting with soon that could potentially have all the parts you'll need for your swap or anyone else who is considering doing this very swap. It is a 5.2L V8 ZJ, 44RE transmission & I believe it is a NP-231J transfer case. Rear axle equipped with disc brakes that can be used on the rear of the TJ and it has the correct exhaust "Y" pipe and serpentine power steering bracket for a TJ swap. The ZJ also has all the heavy duty steering parts to use on a TJ as doccumented here in the forums. It runs but has a bad power steering and transmission leaks that would need to be repaired before it could be a daily driver. It is a Laredo edition with power sun/moon roof. First $600 takes & I have all the California lien sale paperwork so it is NOT salvage titled...... It comes with lots of spare parts including a complete set of axles if someone wants to build a 4-door luxury wheeler.
Hope some of this intel helps...
RR


**Don't know what all this underlining and linking on the bottom paragraph is about... Something wierd going on with trying to post this response this morning.**
 
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Jeepsr4grls89

Jeepsr4grls89

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@RangerRick I can't thank you enough for your wealth of knowledge! This is great information! I plan to take my time and do this gut and rebuild right. I am basically redoing it from the ground up. The body is coming off, new paint, interior etc. The swap is my main concern right now, since I will be doing the engine this winter. I was gifted the 5.9 from my brother, so that is why I chose it. It's out of a Durango.

I watched a gentleman on YouTube (Montana Lowgear is his channel name) and he did the same swap in the same year TJ as I have and there is some great info on that channel as well if anyone else does this swap. I can't wait to get in to it! I think I will be turning my 2 month old baby girl in to a shop baby and a Jeep girl like her momma!
 

Jamison C

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@RangerRick I watched a gentleman on YouTube (Montana Lowgear is his channel name) and he did the same swap in the same year TJ as I have and there is some great info on that channel as well if anyone else does this swap.
I watched his whole series on the swap. The only thing I have to say about that is DON’T move the engine mounts farther back than recommended just to avoid having to change your driveshaft lengths. I’ve seen several threads where people do this and that is such a stupid reason to compromise ideal engine and drivetrain location, weight ratio, ease of access to the back end of the motor, etc. Most of them, including Montana Lowgear end up having to beat the snot out of the firewall for clearance.

A 1.25” body lift will make your life a lot easier too, if you don’t have one already. I think AA (Advanced Adapters) even recommends that. Their mounts are designed around a 5.2/5.9 with an auto tranny but you can absolutely make it work with a manual.
 

RangerRick

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For the most part I agree with @Jamison C regarding engine placement. DON'T beat the snot out of your firewall or try to save on drive shafts and compromise other areas of the swap in the process..... AA has figured this out for you, work with their recommendations unless there is a REALLY good reason not to on motor mount placement.

As far as body mounts go, skip the add-on 1.25" style and go for just the plain 1-piece replacement motor mounts that are 1" taller. I have done a LOT of body lifts and will not be using any lifts that re-use any factory mount hardware again. Not worth it on vehicles that are 20 years old+. And with the more than 50 body mount lifts I had performed when I owned the shop the experience tells it....

AA Magnum motor mounts are definitely the way to go rather than try to kludge something up using the original style mounts that don't hold up well off-road BY THEIR DESIGN. The torque off-roading will shread and rip the factory style mounts apart in short order causing you to risk an engine shift that can cause massive radiator damage and all kinds of other problems. Not worth trying to re-engineer the apple cart here again IMHO.

I also watched Montana-LG's documentation of his swap. I looked at @Wildman 's swap he documented and talked a lot about on another forum. Also looked at member @pcoplin 's swap and chat threads, particularly his experience with outsourced wiring harnesses and the makers repsonses to the problems he had experienced. Research is key here. I read every post on all the major forums including Pirate and their supposed "bible"(which I didn't agree with a lot of), JF's more than 168 pages (at the time), Wrangler forum & the excellent documentation from "Project Culpepper" done by Slangy over on RME4x4. After more than a year of research and gathering parts, I learned what and what NOT to do on my swap before ever spinning a wrench. THIS INCLUDED BUYING AN ENTIRE DONOR ZJ VEHICLE to keep from getting nickle & dime'd to death on the small things.

The key to my swap is I WANTED IT TO LOOK COMPLETELY FACTORY. It had to look AS CLOSE AS POSSIBLE like my Jeep rolled off the assembly line from Jeep with the V8 installed in it. In my research I learned a lot of things and by asking dozens of questions to those members of these other forums that had already done the swap of what pitfalls to look out for.

This is where I learned that I definitely wanted a ZJ Grand Cherokee transmission, the heavier 46RE automatic transmission (if possible over the 44RE), for the passenger side starter motor mounting and the factory "Y" pipe exhaust fitting without totally going crazy on the customized mandrel bender.... It must also pass the stringent CARB (California Air Resources Board) SMOG check program without flagging ANY changes the 1st time out of the gate. I wasn't going to waste time back & forth with the inspectors to get it signed off. It had to pass and not waste my money or time in this process so I used virtually EVERY part I could from either the donor ZJ or the TJ Wrangler including the air intake and filter housings just to get it through the certification process.

My jeep has modifications no doubt with the flat tummy tuck, the V8 conversion, the Rock Jock 60 axles and suspension etc. But the main point is this:

The engine and all it's operation is completely stock. The harness was blended as I said in an earlier post from both the TJ and the ZJ harness and the ECM was from a 1998 Dodge RAM that came equipped with the same powertrain combo I have. It was also a California emissions certified vehicle to boot. Other than the engine and transmission being different, the scan tool read my Jeep as a Dodge 1500 V8 automatic 4x4 pickup, not a 1997 2.5L Automatic TJ Wrangler. That's it.

The radiator has outlets different, the hoses are different but bolts in the same place with the 4.0L shroud and ZJ engine driven fan. There was no way I was going to rely on an electric fan to keep my baby cool in 120* desert temperatures here in the south-west. The serpentine belt, accessories and even the A/C are all stock ZJ or TJ parts. Even the cruise control is factory MOPAR parts. The exhaust from the "Y" pipe down to the catalytic converter is ZJ, the Catalytic convertor to the exhaust tip is TJ Wrangler CARB approved Gale Banks "Monster" stainless exhaust. O2 sensors up & down stream and all sensors or actuators on the engine are factory MOPAR parts, nothing aftermarket.

Since all J-Tech series ECM's Chrysler used in this era of CCD bus computers are the same, it all went together relatively easily and is 100% compatible to run the dash gauges on the TJ. (Note: 1997 Dodge RAM ECM's did not use the ECM to run the gauges so I had to go with the 1998 which did use the ECM to run the gauges in the truck so they would run my TJ dash) also found out about by asking questions and advanced research.

A lot to digest here but none the less, if you want the job done right, better take your time and make it like the factory would have done it.

Sorry to say it but anything else is just a hack job and I don't want that on my Jeep thank you very much.
RR
 
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Jeepsr4grls89

Jeepsr4grls89

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@Jamison C @RangerRick Thank you guys, again, so much. Your experience and knowledge are much appreciated. Yes, I did NOT want to beat the crap out of my firewall. That looks like way too much of a pain. RangerRick THANK YOU for the leads on more places and threads to research. I do, indeed, want to make this look as factory as possible. Granted, here in ND, there are not such strict emission laws. I want this Jeep to last and be good to go for the rest of its life, so something cobbled together is not in the cards for me! :) It will be done to the best of my ability. I guess the harness was my main concern right now just because I am NOT wiring savvy. I am mechanically inclined, but not so much on the electrical part of things. Since this engine came to me as just that, an engine, I still need to hunt down a donor harness and a transmission to use. Those will be next on my list, so suggestions are welcome!
 
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Wojoe

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I am doing a 5.9L swap right now. Just sat the engine in yesterday. Looks like it belonged there all the time. I'm almost done with the wiring. Kind of hung up on transferring the auto trans wires over. Good luck and have fun.
 

TreverStevens

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I know this tread is a couple weeks old now and you might have the answers you wanted, but I am nearing the end of this swap too. I went from a 2.5 manual (Ax5 trans) to the 5.9L (from a Durango) with an NV3550. One of the hardest parts for me (besides time and $$$) was finding someone willing to sell me their Dakota NV3500 bellhousing. Everyone wanted to just sell me the entire trans.

I can't even tell you how many time I watched Montana Low Gear's series. A few issues with his series. He has a few other videos not tied into the Magnum Swap "playlist" that everything is in. He has another video on his channel that he completely goes against pretty much everything he says in his wiring video on that playlist. The video that isn't on the playlist is the "more correct" way of doing the wiring. I thought I had it mostly figured out based off his first video, but then found the other and nearly had to start from the top again. I even emailed back and forth with him a number of times when I first started. He even stated there he kinda gave up on the videos and has a lot of info/footage he never even uploaded. I've tried sending him a few more emails in the past couple months with other questions with no answer, no harsh feelings or anything, I know life gets in the way. Maybe try reaching out to him if you have any other questions though. You might have better luck. He gives his email out in a few videos plus it's in the comments on a few videos too.

The few of the guys on here I've chatted with to pick their brain (@RangerRick and @Paul Ruggles being some of them) are a wellspring of knowledge. I'm shooting to have my project wrapped up by the end of Sept so hopefully I can answer some of the questions too. There's little things to take note of and relying on others' insight helps, but some you'll have to find out on your own. Like I had been told (after being well into my project) that there weren't any manual Ram's with the 5.9 made. Plenty of the Ram and Dakota's with the 5.2 and a manual. But then I found out this past week that wasn't completely true. The Ram 1500's didn't come with the 5.9 and a manual, but there were plenty of Ram 2500's with that setup. So if you buy clutch parts you have to search for 2500 parts.

It's a fairly laborious swap, but there's plenty of aftermarket support and a small community behind it too. So it's do-able.
 
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RangerRick

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I started gathering parts for a second swap including the donor ZJ Grand Cherokee running here so I will be selling parts for another swap soon to anyone interested. I have a complete 1998 ZJ Grand 4x4 that runs but has leaks so can't be driven until they are fixed. It has a 44RE that would be good for the swap but it is a 5.2L Laredo edition, not a 5.9L. There isn't much difference between the two and I can tell you the 5.2 gets way better economy if anyone is interested in parts to do the swap themselves on any 1997-early 2000 TJ FWIW.

I may also have some performance and armor parts from this second build that never happened such as full tub armor, flat fenders, rocker guard sliders, D44 front, another Rock Jock 60 for the rear will fit all years TJ's or LJ's coming available in the next 4 months for anyone interested..... Also a full cage assembled on a basic TJ roll bar already, complete carpet, and seats out of a 2004 Rubicon TJ.

May also have a 4.5" Rubicon Express Superflex lift kit with all adjustable arms coming. I am debating if I am going to sell my whole stash of enough parts to build a 2nd TJ like the V8 I already built.....


RR
 
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TreverStevens

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I may also have some performance and armor parts from this second build that never happened such as full tub armor, flat fenders, rocker guard sliders, D44 front, another Rock Jock 60 for the rear will fit all years TJ's or LJ's coming available in the next 4 months for anyone interested..... Also a full cage assembled on a basic TJ roll bar already, complete carpet, and seats out of a 2004 Rubicon TJ.
I might be interested in some of the armor and fenders. Just send pictures and info whenever you decide what you're doing.
 

TreverStevens

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What is the most rearward slope/angle you guys would recommend on the 5.9? I'm currently sitting around 4* (measurement was taken by putting an angle finder on the mounting flange of the oil pan).
 

TJ99V8

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I just registered today as I am starting the process of swapping the current 2.5L AX5 out for a stock 5.9L Magnum from a 98 Ram auto, and using an upgraded AX15 from Novak. I had the ECU flashed by B&G to remove the auto, and have the wiring harnesses all blended. I have most of the parts with the exception of a radiator/fan/shroud, and figuring out the clutch. Does anyone know if I can simply use a stock 12" clutch with 12" flywheel from a Ram 2500 in my setup? How about crank position sensor? Will I need to change the master/slave cylinders or can I reuse existing? I have a long way to go, but want all the parts in hand. Any experience or recommendations are much appreciated.
 

TreverStevens

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I'm about the same point in my swap. My CPS didn't work once the flywheel was bolted on. Haven't decided yet if I'm going to find a different sensor or just stack 3 washers under where the sensor bolts up to give me the clearance I need. Here's the flywheel I bought (https://www.summitracing.com/parts/pft-50-2754) and I bought a new clutch kit (https://www.summitracing.com/parts/ctf-cf178066) because I wasn't sure if the stock TJ setup would work. I think the master and slave cylinders will still work because I never heard about anyone else having to do anything to the stock ones in my research.
 

TJ99V8

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Thanks. I ended up ordering that same flywheel via RockAuto as it came with the flywheel, clutch, throwout, and new master/slave (even if I dont' need them) - Kit p/n for anyone interested was Perfection Clutch MU20501SKP . Figured I'd try it out and if it rubs the inside of the bell as Novak said they've seen happen in "some cases", I'll deal with it then. If your set up is good, mine should be too - depends on the height of the clutch housing. I also heard the same that the stock slave/master will work and that many have just put washers or a spacer for the CPS with success. Keep me posted on your progress, I can't wait to pull this old 4 banger and get moving on this! Lots to still figure out with little details like radiators and fans, exhaust, hooking up fuel lines, etc... but small things. Good luck!