Hemi TJ Questions

BlueJayTJ

BlueJayTJ

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Joined
Aug 30, 2023
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15
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Columbia, MS - 39429
Lets get this thing started! I have a 2000 Wrangler TJ with the 4.0 and 32RH mated to the NP231J:

IMG_7046.jpeg


I am rebuilding a 3rd Gen Eagle Hemi to eventually go in it. According to this article:

https://www.autoweek.com/news/a2069...ngler-hemi-yeah-its-got-hemi-and-you-can-get/

they state that: "To create our particular test vehicle, AEV started out with a 2004 Wrangler Rubicon. The company then had the 5.7-liter Hemi V8 and five-speed automatic yanked from a 2005 Dodge Durango, the powertrain hooked up to the Rubicon’s original transfer case and 4:1 low-range gearing tossed in."

My question is: which transmission are they referring to and will it also bolt up to the Non Rubicon transfer case that I have (NP231J).

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I believe the transmission is the 545RFE 5 speed auto. I *think* tcase bolts up to the 545RFE but I've read there are a few different output shafts on the 545 RFE. You need to verify spline count obviously, but I also have read that some have a longer output shaft that either needs to be trimmed, or I believe they sell a spacer plate.

I'm sure others will chime in, and if I'm wrong please let me know and I'll edit the post.
 
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You will certainly need a bit more info to pull this off than what is in this article. Where else are you getting information? Lots of it out there.

You mentioned you have the eagle head hemi which implies a later year. What year is the mill you have, and from what was it pulled?

Two problems with the later stuff. Solvable, but problems no less. On the later mills the configuration of the accessories will require clearancing the frame, and it makes for a much more difficult install compared to the earlier stuff. Also, the electronics on the later engines will not communicate with the stock TJ instruments, necessitating their replacement. You can sometimes get away with running an earlier ECU, but it depends on the engine you are using.

Hardtail is correct on his tranny info. It’s not just the spline count, it is also getting the correct shaft length. Get those right and it will work with the 231.
 
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So now I really enjoy my 32RH after having it for a while, it is fun on the trails and even at 70-75mph it has not let me down. With that being said, I am wanting ANY information as to whether a 318 (“newer” magnum 318”) would bolt right up to the 32RH. If it will, I would much rather just do that because it would require far less work. Any help is much appreciated.
 
BlueJayTJ said:
So now I really enjoy my 32RH after having it for a while, it is fun on the trails and even at 70-75mph it has not let me down. With that being said, I am wanting ANY information as to whether a 318 (“newer” magnum 318”) would bolt right up to the 32RH. If it will, I would much rather just do that because it would require far less work. Any help is much appreciated.
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No a 5.2 Magnum V-8 will not just bolt right up to your 32RH and even if it would the 32RH wouldn't be strong enough to handle the power of the V-8.

You need a 44RE or 46RE transmission which come behind the 5.2 (318) or 5.9 (360) in Dodge pickups, Durangos & Dakotas or Grand Cherokees.

The nice thing about these transmissions is that the NP231 will bolt up to it if the spline count is correct. I'm not sure what spline count was used on the auto transmission.
The other good thing about doing a Magnum V-8 swap is that the blending of the two wiring harnesses isn't that hard and is about 14-18 wires total. The Dodge PCM mounts in the same position as the Jeep PCM. Since you have an automatic already doing the swap is easier than someone doing the swap that had a manual.

Here is a good thread to read on the Magnum swap.

https://www.jeepforum.com/threads/wrangler-magnum-v8-discussion.1365878/
 
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Wildman said:
No a 5.2 Magnum V-8 will not just bolt right up to your 32RH and even if it would the 32RH wouldn't be strong enough to handle the power of the V-8.

You need a 44RE or 46RE transmission which come behind the 5.2 (318) or 5.9 (360) in Dodge pickups, Durangos & Dakotas or Grand Cherokees.

The nice thing about these transmissions is that the NP231 will bolt up to it if the spline count is correct. I'm not sure what spline count was used on the auto transmission.
The other good thing about doing a Magnum V-8 swap is that the blending of the two wiring harnesses isn't that hard and is about 14-18 wires total. The Dodge PCM mounts in the same position as the Jeep PCM. Since you have an automatic already doing the swap is easier than someone doing the swap that had a manual.

Here is a good thread to read on the Magnum swap.

https://www.jeepforum.com/threads/wrangler-magnum-v8-discussion.1365878/
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See my dilemma is, I have a 2012 5.7 Hemi, it needs to be rebuilt but I have most everything already to do that with. If I were to put this in the TJ I’d need to locate a 545RFE which would also accept my NP231. I just don’t know what to do now.
 
BlueJayTJ said:
See my dilemma is, I have a 2012 5.7 Hemi, it needs to be rebuilt but I have most everything already to do that with. If I were to put this in the TJ I’d need to locate a 545RFE which would also accept my NP231. I just don’t know what to do now.
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If I was doing the swap NOW as opposed to 2006 when I first did my swap I'd do a Hemi hands down. Back in 2006 they were just too expensive which was why I did the Magnum V-8.

But some things to consider. You'll need a different dash & wiring harness since your dash is a CCD dash and you need a PCI dash. There is a LOT more work required swap the Hemi into your TJ. Starting with a newer TJ makes some of this easier.

BTW I like the color of your TJ.

Doing a Magnum V-8 swap will be easier. The one thing to note is the Magnum engine doesn't make as much power as a Hemi. Can they? Yes but it isn't cheap. Is doing a Hemi swap on an older TJ impossible? Nope it's just more work.

Either way you're going to need a new transmission, either a 46RE or a 545RFE. The 46RE is a 4 speed auto & the 545 is a 5 speed auto.
 
Wildman said:
If I was doing the swap NOW as opposed to 2006 when I first did my swap I'd do a Hemi hands down. Back in 2006 they were just too expensive which was why I did the Magnum V-8.

But some things to consider. You'll need a different dash & wiring harness since your dash is a CCD dash and you need a PCI dash. There is a LOT more work required swap the Hemi into your TJ. Starting with a newer TJ makes some of this easier.

BTW I like the color of your TJ.

Doing a Magnum V-8 swap will be easier. The one thing to note is the Magnum engine doesn't make as much power as a Hemi. Can they? Yes but it isn't cheap. Is doing a Hemi swap on an older TJ impossible? Nope it's just more work.

Either way you're going to need a new transmission, either a 46RE or a 545RFE. The 46RE is a 4 speed auto & the 545 is a 5 speed auto.
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Man thank you so much, you really are extremely knowledgeable about this. Thank you on the color. I have NO IDEA what the color is because it was Patriot Blue from the factory. I purchased it from my uncle who was the second owner. The original owner did the paint on it and I love it. I’m planning on also doing a DIY High Line fender conversion because AEV is just my fave, but I’m going to wrap the entire jeep after that is done and I want it as close to this color as possible. I sold my 2021 Gladiator to purchase this TJ and I don’t regret it at all.
 
BlueJayTJ said:
Man thank you so much, you really are extremely knowledgeable about this. Thank you on the color. I have NO IDEA what the color is because it was Patriot Blue from the factory. I purchased it from my uncle who was the second owner. The original owner did the paint on it and I love it. I’m planning on also doing a DIY High Line fender conversion because AEV is just my fave, but I’m going to wrap the entire jeep after that is done and I want it as close to this color as possible. I sold my 2021 Gladiator to purchase this TJ and I don’t regret it at all.
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Let me know if I can answer any other questions for you. I enjoy these swaps and talking about them too. When it comes to doing a V-8 swap I'm more inclined to use a Mopar engine over the popular LS engine.

You have a Dana 35 rear axle so if you do a V-8 swap just know that you'll need replace it also as the Dana 35 won't handle the power of a V-8.
 
BlueJayTJ said:
Yeah you’re not too far from MS. It’s gonna be a while but I will let you know for sure. Going to be hard to part with it.
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What are your end goals? Are you wanting the V-8 for more power to run larger tires? If so how large of a tire are you wanting to run? Setting your goals first is the BIG part of figuring out what to do. Then working towards those goals as cost effectively as possible. When I'd first built my TJ I hadn't planned on ever going larger than 35" tires so I'd built my axles accordingly. Then 2 years later I went to 38" tires. During this rebuild I went with 38" tires again but they are wider plus I'd changed wheels so I had to install 1.25" spacers to accommodate those wheels. Which now makes my front axle not the best deal in the world. It'll work for now until I can build a new front axle.
Since you have the Hemi already it seems logical to build towards that. But the Magnum V-8 can be found in a lot of cheaper rigs and you can build a nice rig with it. So figure that out first and then build from there.

@NashvilleTJ can probably answer these questions better or @Daubie3 or @Gassiper who all have a Hemi in their rigs. If you have a newer block can you run the earlier accessory drive to make things fit better?

Once you've figured out which engine then choose your transmission. You have the 545RFE or the newer 8HP70 which is a 8 speed auto.

Here's some threads on doing a Hemi swap:

https://wranglertjforum.com/threads/gen-iii-hemi-swap-into-tj—reference-guide-swap-info.46347/
https://wranglertjforum.com/threads/hemi-swap-resource-thread.37529/

A couple Hemi swaps of members.

https://wranglertjforum.com/threads/daubies-at-home-hemi-conversion.67473/

https://wranglertjforum.com/threads/6-1-ljr-build.67130/
https://wranglertjforum.com/threads/nashville-tjs-build-continued.42035/

There is a lot of information out there on doing either one of the swaps. So research first and figure out what you're doing and then build it from there. And start a build thread so others can help you out when you need it.
 
BlueJayTJ said:
See my dilemma is, I have a 2012 5.7 Hemi
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Keep in mind that "i have a motor in the garage and i want to make it work" is almost never a good idea. You'll be saving time,money,and problems by researching which motors go in that jeep with the least issues and make a plan.then selling what you have and buying what you need. Typically a whole donor vehicle that has 90% of what you need
 
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Check out hotwire auto.com Lots of info for hemi swap into Tj. I believe they recommend up to a 09 engine with a 05 ram pcm to work with stock gauges.
 
This is one of the better video series' I've seen on the Hemi swaps. Dumbs it down for guys like me:

 
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