2006 RHD TJ Wrangler to Kubota V1903/AW4/NP231J Swap
 

Hey DieselBombers!

So I'm a huge diesel fan, my daily is a 2006 Jeep Liberty CRD, has an eco-tune on it, and I average about 29~31 mpg and absolutely love it! However my favorite Jeep is my 2006 Jeep Wrangler that is Right Hand Drive. I'm the second owner, I bought it from a lady who bought it new from Jeep. I purchased the Wrangler last summer. It's got the 4.0L with the 42RLE automatic transmission and a NP231-J transfer case. Runs great, just hit 200K however I'm getting sick of 15~17mpg and no power or torque unless I rev the crap out of it. So out with the 4.0 and in with the Kubota Diesel! Anyway here is my Wrangler:

https://cimg7.ibsrv.net/gimg/www.die...d8960877da.jpg

So here is the plan, install my Kubota V1903 4-cylinder engine mated to an AW4 4-speed automatic out of a Cherokee to my NP231-J transfer case. I picked up the V1903 in 2016 for another build, but I've decided to go with a V2203 for my other build and use the V1903 on this build since I don't plan on going to a larger tire.

https://cimg4.ibsrv.net/gimg/www.die...4fdaaceaef.jpg
https://cimg5.ibsrv.net/gimg/www.die...7466bac9a2.jpg

For the transmission I'm going to use the AW4 for a couple of reasons. First I enjoy the automatic off-road. I injured my left knee a few years ago and it's easier for me to wheel off-road with an automatic where I don't have to clutch. Also has the added benefit that my kids like to go off-roading with me when the Jeeps automatic! Second there is no after-market controller that I know of that can control the factory 42RLE transmission in my Wrangler currently. The AW4 can be manually shifted, and I'm looking into an Arduino based shifting solution as well for the AW4. Third I don't want to have to adapt my NP231-J to another transmission, by keeping all the parts Jeep, it will help reduce cost and keep maintenance simpler in the future. I bought a working AW4 with 90K on it about two weeks ago, I still need to get a torque converter and a flywheel. I'm not sure the torque converter and flywheel that are currently on my Wrangler are compatible.

https://cimg4.ibsrv.net/gimg/www.die...e67e7cc9f5.jpg

Here is a short list of things I'm looking to do on this build:

• Swap in Kubota V1903 Diesel Engine
• Install GT15 turbo (already have it so might as well use it)
• Retain my working AC, Power Steering, and Brakes
• Swap out my 42RLE for an AW4 automatic
• Install a Teralow 2-Low Kit in my NP231-J
• Install an Extreme Short SYE kit on my NP231-J
• Install custom Autometer gauges
• Modify Cruise Control to work with factory Steering Wheel controls
• Possible 3.55 gear swap for improved MPG

I'm going to be using an adapter and parts from Ken at KubotaSwappers.com for this conversion. I've already had the pleasure of talking to Ken several times on the phone both about this project, and my other build that I'm doing at the same time.

My end goal is to retain my AC, Power Steering, and Cruise Control on my Wrangler while looking to obtain around 40mpg highway, preferably more. I really want to be able to take this Wrangler to the beach or to a cabin and not spend a fortune on fuel. Also I hate being told, you want go mileage get a Prius or a Honda. My Jeep Liberty gets great mileage so I don't see why my Wrangler can't either.

My gearing right now is 3.73 and the AW4 has a final gear of 0.75. I'm currently running a 235/75r15 Goodyear Wrangler tire because they are dirt cheap and do great in any weather condition and are decent for the light wheeling. I'm considering looking into going with a 3.55 gearing possibly down the road to get my better MPG.

SO time frame. I work a full-time and share custody of my kids, so I will be working on this whenever I can, my hope is to have this conversion done in 2018, right now I'm still gather parts from everywhere and I haven't even started tearing my Wrangler apart. As I get parts and pieces in I will post updates on my progress!

Feel free to give advice, I know there are several areas I'm still having to figure out, primarily wiring, power brakes, and fueling.

Thanks and hope ya'll enjoy the build!
-Grant

Hey Grant
Ken here, I missed this thread.

I just ran the gearing calc finally and compared your 3.73 to 3.55s

At 65 mph with 3.73s you are at 2116 rpm
With 3.55 you are at 2013 rpm

If you went with a 30" tall tire instead of you 235s on your 3.73s you would be at 2037rpm.

I would suggest not doing gears/ axles and just bumping up tire size.

Lots less work involved. But firstly get it on the road and bugs worked out. Then see where you want to go.

Also as we discuss over the phone the IDI will not be as efficient as a DI.

Hoping to get your kit out soon. Just trying to get parts in the lathe and i can get the water pump pulley done and out the door!

Ken

Well another month has passed and I'm still gathering parts, which seems to take forever. Also work has just obliterated any of my free time in the last month. However I have the first two weeks of July off so I will be doing the majority of the conversion on the Wrangler then!!!

First new parts!!! I got a flywheel, bolts, torque converter and GPS Speedometer gauge in for my Wrangler, all took longer to find and source than I was expecting:

Attachment 62655

I knew my Ken at KubotaSwappers was backed up but found out today most of my parts shipped!!! Not all of them, will still be waiting on some, but the parts I need to get the V1903 in the Wrangler and mated to my AW4 are coming!!! Here are some of the pictures I got from Ken!!!

Attachment 62656

Attachment 62657

Also I'm getting to the point where I think I'm going to run at least 3 separate Arduino system on the Wrangler. I'm going to run my AW4 with an Arduino, a separate Arduino for Cruise Control, and now I'm debating keeping my stock gauges and running them with Arduino. Not sure on the last one, I have another project all my gauges can go into so it won't be a lose just still not sure how I want to tackle the project yet!

I do have a GoPro Hero5 Session coming in from Amazon, so I was thinking about doing a time lapse of the entire project and posting it daily to youtube if anyone is interested!

Thank you so much!
Grant

I just wanted to let you know i did an s10 with jeep straight axle swap and the 2203di with a turbo and i could never get the truck to get out of its own way with the auto trans and i changed converters twice still no luck ended up melting pistons the other s10 i have is two wheel drive and 5 speed and i am going on 4 years still going great just wanted to put that out there because it cost a lot of time and money

:nice: Wow that is interesting to hear! What automatic where you running? I really wasn't planning on doing a automatic to manual conversion, I really like the control the automatic gives me off-road with my driving style. I've got a 2000 stall heavy duty torque converter that I was hoping would work well. It's surprisingly difficult to find a low stall converter for the AW4, though I think I can get one custom made.

Also I'm probably going to rewire the cruise control buttons on my steering wheel to manually upshift and downshift my AW4, so I can control when the Jeep up shifts and down shifts.

Thanks
Grant

I used a 700r4 that was built for a diesel and the stall was too low because the engine dose not have the toque of a big diesel i ended up with a 2200 stall gas converter to get 1400 rpm out of it

I have used both the 700r4 and the AW4 in diesel swaps, hated the 700r4 loved the AW4. I used the stock converter in the AW4 and it was perfect, I don't believe the stall was as high as you're using. I also used the stock trans controller, once I got the TPS dialed in it performed great.

I am glad someone has used that trans with good luck i just hate to see someone put a ton of time money and work into something and end up melting pistons

The 700r4 has a horrible 1st-2nd gear jump. Not great for a low rpm diesel.

The stock stall on a jeep 4.0l aw4 is supposed to be 2200-2300. They are very loose. Dropping stall speed and maybe installing a aw4 shift improver kit would be good. It ads extra line pressure down low.



Ken

Yeah I'm debating trying to get a pre-1997 stock controller working or just going with a full manual setup, not sure yet. I really do want a automatic transmission for my Wrangler, I'm surprised by how much I prefer it. I do have that 2000-stall heavy duty torque converter so I'm looking forward to getting that figured out!

Hey Ken,

Thanks for the info, I'll look into doing a shift kit on the AW4 as well to increase the line pressure as well! BTW I'm going to start documenting everything with both pictures and video on Youtube so I will post links once I start getting progress made hopefully starting around next week!

Thanks
Grant