Building a diesel powered RHD TJ Wrangler (Picture Heavy)

RustyAutoholicGuy

Diesel Wrangler Guy
Supporting Member
Joined
Aug 1, 2018
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1,571
Location
Virginia
Hey TJers,

This has been my 4 year, so far, journey to making my Right Hand Drive TJ Wrangler powered by a diesel engine. First off here is a picture of my 2006 Jeep Wrangler Right Hand Drive when I started back in 2018:

IMG_20170622_095531845.jpg


Here is the most recent picture of my TJ Wrangler:
IMG_6974.jpg


Here is a quick update of my build to date:

Version 1 of the swap:
Kubota V2403 Mechanical Turbo diesel with an AW4 4-speed automatic

Version 2 of this swap:
Kubota V2403 Mechanical Turbo diesel with a Ford 6r80 6-speed automatic

Version 3 of this swap:
VW ALH TDI with Ford 6r80 6-speed automatic

Version 4 of this swap:
VW BEW TDI with Ford 6r80 6-speed automatic

Version 5 of this swap:
VW BEW TDI with AW4 4-speed automatic

I'll be updating each Version with post links for reference.


*ORIGINAL POST*
My TJ is pretty much bone stock, has just over 200K, 4.0L, 42RLE auto with a NP231-J transfer case. Has factory air conditioning that works, power steering, and cruise control which I added after I bought the Wrangler. Currently has a Dana 44 in the rear with a factory LSD on Goodyear Wrangler 235/75r15 tires which are great year round and dirt cheap.

I bought the Wrangler last summer, it was my first Wrangler and I love it, except for gas mileage. My daily driver is a 2006 Jeep Liberty CRD 2.8l turbo diesel, which gets fantastic mileage and has a ton of torque. The Wrangler gets around 13 ~ 17 mpg, my Liberty gets just above 30mph highway, consistently 28 ~ 30mpg. Here's a picture of my Liberty:

pX4w7kwl.jpg


The transmission I will be using is an AW4 out of a Cherokee.

FbUwrGCl.jpg


I'm going with the AW4 for multiple reasons. First I injured my left knee a few years ago, and while I love manual transmissions, an automatic makes off-roading so much more fun for me personally. Also has the added benefit that my kids prefer it as well, so they go on more wheeling adventures when we are in my automatic Wrangler.

Second I can just manual shift the AW4 by controlling two solenoids. Third I don't have to get an adapter from my NP231-J transfer case which is a huge cost savings as well. Really the main issue is there is no aftermarket transmission controller for the 42RLE transmission that is currently in my TJ, plus it has over 200K on it.

I'm going to be controlling the AW4 automatic transmission with an Arduino setup so hopefully later on I can program the Arduino to shift the AW4 automatically, but at the beginning it will just be a manual shift.

For transfer case I'll be using a rebuilt NP231-J that already has a SYE installed.

The Kubota V2403 Diesel engine should be perfect for this swap. I will have the horsepower of the 2.5L and way more torque than the 4.0!

0BULeNPl.jpg


I'm getting my adapter from Ken at KubotaSwappers.com. He is making me an adapter plate and accessory brackets and motor mounts so I can still have my air conditioning and Power Steering on my TJ.

In talking to Ken, he tells me I'll probably be closer to 110hp, and 300ish /lb once I dial in the turbo and the fuel pump on the V2403. The Kubota's from the factory were really detuned for reliability so they are running around 30% of their max fuel settings.

Now for the important bit! In talking with Ken from KubotaSwappers, from his experience in swapping these Kubota engines into XJ Cherokees, he said I should get into the mid 30s for MPG, depending on speed and gearing.

Right now I have 3.73 gears, which I'm going to leave alone until after I get the TJ running and see how it does. I might be doing a gear swap to 3.55s later on, not sure yet. My goal for my mileage will be 30 ~ 34mpg, effectively doubling my current MPG. However I'm really hoping to tune the turbo and fuel pump to get my closer to the 40mpg mark but really anything over 30mpg is going to be a win.


Why am I not lifting my Wrangler? I might in the future but I was my Wrangler back on the road asap!

Let me know what you think! I'm currently in the phase of getting all the parts I need, which has already been more than I was initially thinking. I will be posing updates each day I get new parts in or when I start getting the Wrangler torn done for the swap!

If you have any questions feel free to ask!

Thanks
Grant

tAMEImJl.jpg
 
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Very interesting. Let us know his much this will cost

So roughly for all the parts that I have shown I'm into the entire build for about 3K total. If I had used the original Kubota Diesel engine I had, a V1903 which is now being used for another project, The cost of this diesel swap would be closer to $2200. I will say this does not take into account anything I have missed and the small little items you end up having to buy during the project!

Interesting swap. Going to follow out of pure curiosity. What is the Kubota diesel originally out of?

I believe a Kubota tractor but I'm not sure. I bought this V2403 from a guy in Michigan who got the engine in trade so I'm not sure what the engine came out of!

Wow, this is something you don't see every day!

Exactly! The right hand drive is neat by it self, but to have a fuel efficient Wrangler with a ton of torque is going to be amazing! Ken at Kubota Swappers estimates I should be anywhere between 32 ~ 36 miles per gallon with proper tuning. He also told me I could increase it further with doing a lift and some bigger tires, but for now I'm going to run what I have so I can get the Wrangler back on the road as soon as possible!

Thanks
Grant
 
Exactly! The right hand drive is neat by it self, but to have a fuel efficient Wrangler with a ton of torque is going to be amazing! Ken at Kubota Swappers estimates I should be anywhere between 32 ~ 36 miles per gallon with proper tuning. He also told me I could increase it further with doing a lift and some bigger tires, but for now I'm going to run what I have so I can get the Wrangler back on the road as soon as possible!

Once it's all said and done though, do you think it will have considerably more power than the factory 4.0?

I'd always thought the CRD engine from the 05-06 Liberty might make a decent swap, but for whatever reason or another, I don't see anyone do that swap.

It sure would be awesome to get that sort of MPG out of a Wrangler!
 
Once it's all said and done though, do you think it will have considerably more power than the factory 4.0?

I'd always thought the CRD engine from the 05-06 Liberty might make a decent swap, but for whatever reason or another, I don't see anyone do that swap.

It sure would be awesome to get that sort of MPG out of a Wrangler!

My daily driver is actually a 2006 Jeep Liberty CRD and I can tell you why no one does that swap! I love my Liberty but that engine is one of the more difficult engines to work on and the computer is so integrated with the motor the wiring around that swap would be a nightmare! THAT BEING SAID I have put 120K on my Liberty in 4 years and it's never missed a beat!

This setup will have considerable more torque the factory 4.0l! I believe my 4.0 makes peak torque of 235ft-lbs around 3200rpm where as this V2403 is going to be making 300ft-lb from basically 1600rpm ~ 3000rpm so the torque is going to amazing, no more down shifting the transmission climbing hills and mountains while I'm on a highway or interstate! Horsepower will be considerably lower but I'm not worried about acceleration, at round 120ish HP I will have more than enough to accelerate onto highways and interstates.

Thanks
-Grant
 
My daily driver is actually a 2006 Jeep Liberty CRD and I can tell you why no one does that swap! I love my Liberty but that engine is one of the more difficult engines to work on and the computer is so integrated with the motor the wiring around that swap would be a nightmare! THAT BEING SAID I have put 120K on my Liberty in 4 years and it's never missed a beat!

This setup will have considerable more torque the factory 4.0l! I believe my 4.0 makes peak torque of 235ft-lbs around 3200rpm where as this V2403 is going to be making 300ft-lb from basically 1600rpm ~ 3000rpm so the torque is going to amazing, no more down shifting the transmission climbing hills and mountains while I'm on a highway or interstate! Horsepower will be considerably lower but I'm not worried about acceleration, at round 120ish HP I will have more than enough to accelerate onto highways and interstates.

Thanks
-Grant

Interesting! I had heard that about the CRD Liberty engine too, that it’s hard to work on.

That’s the problem with my existing setup. I have the 42RLE transmission (I really prefer an automatic), but the issue is that if I were to do a swap, I would have to find a different automatic transmission to run, since this 42RLE runs of the same PCM that the 4.0 does, so it’s 100% computer controlled.
 
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Interesting! I had heard that about the CRD Liberty engine too, that it’s hard to work on.

That’s the problem with my existing setup. I have the 42RLE transmission (I really prefer an automatic), but the issue is that if I were to do a swap, I would have to find a different automatic transmission to run, since this 42RLE runs of the same PCM that the 4.0 does, so it’s 100% computer controlled.

I ran into the same issues which is why I'm going with the AW4 transmission! It's a great automatic, can handle the torque and abuse that I'm going to be throwing at it, and I can connect MicroSquirt as a transmission controller to control the AW4! Off-roading for me, automatic is the way to go! I would have liked to keep the 42RLE because it has a slightly better overdrive but there is just no support for an aftermarket TCM which I think is really a huge shame!

-Grant
 
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I ran into the same issues which is why I'm going with the AW4 transmission! It's a great automatic, can handle the torque and abuse that I'm going to be throwing at it, and I can connect MicroSquirt as a transmission controller to control the AW4! Off-roading for me, automatic is the way to go! I would have liked to keep the 42RLE because it has a slightly better overdrive but there is just no support for an aftermarket TCM which I think is really a huge shame!

-Grant

I totally agree! And admittedly, the only reason I'm so attached to my 42RLE is because of the RubiCrawler auxiliary crawl box. With any other transmission my only real option would be an Atlas 4-speed.

Once it's all said and done, what do you think you'll have ended up spending on this swap?
 
I totally agree! And admittedly, the only reason I'm so attached to my 42RLE is because of the RubiCrawler auxiliary crawl box. With any other transmission my only real option would be an Atlas 4-speed.

Once it's all said and done, what do you think you'll have ended up spending on this swap?

Honestly it's looking to be close to $3500 for everything I have, but if you just want to do the swap with the AW4 and NP231-J transfer case you could get the swap done easily for closer to $2500, I found the V2403 and spent quite a bit to get it shipped to me, if I stuck with the V1903 it would have been way cheaper but I'm going to be using that engine for another Jeep build I have planned!

Also my long term plan for my transfer case is doing a NP231-J doubler, it's just a hare shorter than an Atlas but WAY cheaper. I like to keep as many parts Jeep as possible to keep the cost down!

-Grant
 
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Honestly it's looking to be close to $3500 for everything I have, but if you just want to do the swap with the AW4 and NP231-J transfer case you could get the swap done easily for closer to $2500, I found the V2403 and spent quite a bit to get it shipped to me, if I stuck with the V1903 it would have been way cheaper but I'm going to be using that engine for another Jeep build I have planned!

Also my long term plan for my transfer case is doing a NP231-J doubler, it's just a hare shorter than an Atlas but WAY cheaper. I like to keep as many parts Jeep as possible to keep the cost down!

-Grant

Wow! When you consider what people are spending to put in a Cummins R2.8, this swap looks like the deal of the century!
 
Wow! When you consider what people are spending to put in a Cummins R2.8, this swap looks like the deal of the century!

The R2.8 Cummins though is 50 state emissions legal which is why it's so great in many places. Here where I live there are no laws around motor swaps and I don't have any emissions to pass either so I'm able to do this swap without any issues.

HOWEVER with that being said yes I agree, this is a great swap in terms of the cost, and just the cost saving in the mileage I'll get from the diesel vs the gasoline engine will pay for itself in about a year as well!

-Grant
 
The R2.8 Cummins though is 50 state emissions legal which is why it's so great in many places. Here where I live there are no laws around motor swaps and I don't have any emissions to pass either so I'm able to do this swap without any issues.

HOWEVER with that being said yes I agree, this is a great swap in terms of the cost, and just the cost saving in the mileage I'll get from the diesel vs the gasoline engine will pay for itself in about a year as well!

-Grant

It's the same where I live in Salem, Oregon. No emissions, no inspections, nothing. I could put whatever engine I want in my TJ and never have to worry about it, which is why it's something I consider.

I have to admit man, the idea of getting that kind of MPG from a Wrangler makes it very tempting!
 
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It's the same where I live in Salem, Oregon. No emissions, no inspections, nothing. I could put whatever engine I want in my TJ and never have to worry about it, which is why it's something I consider.

I have to admit man, the idea of getting that kind of MPG from a Wrangler makes it very tempting!

My entire goal with this project was to have a TJ Wrangler that got well over 30 mpg but would be amazing off-road as well! I do wonder if I should have put the V1903 1.9L in this Wrangler, I'm currently saving it for another Jeep project. The way I see it is I loved driving my TJ in the summer time but the gas mileage so horrible and it got even worst when I took it off-roading with my kids that switching it to diesel to get the improved MPG and also the greater low end torque so I didn't have to rev the engine as much to spin the drivetrain was a win-win in my book!

Honestly once this project is done, this TJ will probably become my daily, I love my Liberty I truly do, but a TJ that has 300ft-lbs of torque starting at like 1600rpm and can get over 30mpg, I'm going to drive it everywhere!

OH also I didn't actually say this but the kit I got from Ken at KubotaSwappers will let me keep my Air Conditioning, Heat, Power Steering, Power Brakes and I'm working on figuring out how to adapter the factory cruise control to the Kubota diesel as well! I really am aiming to make this a complete swap!

The real test this setup is going to be when I go to Moab. I want this Wrangler to be able to drive from Virginia to Utah, do some light wheeling because it is mostly stock still, and make the trip back home without breaking the bank on fuel!

I did realize earlier I still hadn't order a diesel specific catalytic converter. While I technically don't need it for emission, I do want to reduce my carbon footprint as much as possible and there are so really interesting cats out there now for diesel that really help clean up the exhaust gases as well as reduce the smell of the diesel exhaust as well. I love Jeeps because they allow you to see parts of our beautiful world that you wouldn't normally see so I'm going to do whatever I can to make this TJ Wrangler as eco-friendly as possible!

This is going to be a fascinating build to witness. :thumbsup:

Thank you so much! I spent the better part of a year planning out how I was going to make this happen! I'm spent so much time consulting Ken at KubotaSwappers over how to do this build! I feel like I have the majority of the planning done with almost all the parts I need!

Thanks
Grant
 
Intresting build and I don't have any expertise in the matter but I doubt you'll double the mileage with the swap though since the jeep has the aerodynamics of a cow. But this will be great to follow.

I was doubtful as well, but I'm going off past builds that Ken at KubotaSwappers has done and helped other people with. Since the rest of my Wrangler is stock and not lifted he thinks we can get into the low to mid 30s, but honestly, even if I only double my current MPG which would get me to 28 mpg that would me a massive win as well!