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Wrangler JKU Diesel Swap

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help!
37K views 16 replies 13 participants last post by  Digger84  
#1 ·
Good day everybody,
I hope this message finds you all to be healthy, & safe. So, my jeep broke down outside of Reno 5 days ago & I had to leave it there at a shop, & I’ve got to go out there to trailer it back home. My 2012 Wrangler JKU Sport with a Pentastar 3.6 V6 had misfires on the 2nd, 4th, & 5th cylinders & had oil present in them, burnt exhaust valves, and warped cyl. heads $5200.00 & my 6speed manual tranny has stopped operating!. 2nd, 3rd, and my Reverse are severely damaged. New 6speed?=$10k-$11k. Remanufactured Mopar Trans-$6800. Plus $3500 labor Overall? anywhere between $14-$16k just to bring it back to operating OEM status. If I’m gonna spend that kind of money on my jeep I’m not going to do it to bring it back to OEM!
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“In for a penny in for a pound“. I’m interested in what input you all have in order to shine a brighter light on my current problem. I know that most of you are much more seasoned Jeeper‘s than myself, and I respect what you have to say in its entirety. I’ve been researching the Cummins line of Diesel engines that are offered for the swap, and there are a few options. The Cummins 4BTAA model seems the most simplistic due to the fact it’s all mechanical. I’m not really interested in their 2.8 because it’s just too small. Big Bear Engine Company out of Colorado has some great options as does Bruiser Conversions out of Florida. Big Bear only offers the engines and does not do the swap. Even Caterpillar has a Diesel engine for a swap. I’m just not sure as which way to go with this. I have the shop and tools necessary to do the work, which may take longer than a shop designed for the swap, but I just want to make the BEST most EFFICIENT decision that I can. I’m in California, so the emissions laws here are stringent. I do however have the ability to register it out of state because I’ve got Navy buddies all over the nation that will help out with that. Not only will I have to swap engines, but I’ll have to swap my current Dana 30 axles to Dana 60’s to handle the torque, as well as drive lines. I know it’s going to be costly, but at this point I don’t know what else to do. I bought this rig from a dealership in Oct. 2019 and am still making payments through financing. I’m pretty much caught in a net of which way to go on this. I’ve already invested many many hours of time and approximately $10k in aftermarket parts and accessories. Plus I just love my Jeep & enjoy working on it. It’s become part of me. I’ve put together about $22k in just the last few days so I can do this conversion and purchase whatever is necessary to make this happen. I know it’s a lot of money & I may need more to do this, but when I’m done with this my Jeep will be much more durable, have better fuel economy, and be one bad mamma jamma!
I’m more than interested in what you ALL have to say & ready to listen to your input and/or advice. I hope you and your families are safe and well. May God bless you all. Godspeed.
 
#3 ·
I've wheeled with diesels before, for our style (trails) I would not install one. Honestly most of them just stink up and smoke up the trail.
If it's wide open terrain maybe it's different???

I'm starting to research engine swaps as I know it will be sooner, rather than later, for our '14. Right now that research has led me to MoTech with an LT and 10 speed swap. MOTECH PREMIUM CONVERSIONS And they're emissions compliant on most swaps. They can install at their shop in Las Vegas, or you can order a kit and do it yourself.

Whichever way you go I encourage you to free up some airflow on the front of your Jeep. Between the lights, winch and grill it doesn't look like it's friendly for any engine. IMO

Good luck, sounds like you'll have a nice Jeep when you're done (y)
 
#6 ·
I'm starting to research engine swaps as I know it will be sooner, rather than later, for our '14. Right now that research has led me to MoTech with an LT and 10 speed swap.
10 speed is going to bore you to death. I have a 9 speed in my car and it's a great transmission, but boring, even with 430HP. MT all the way!
 
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#4 ·
The 2.8 crate motor with the new 8 speed transmission would likely work for you. It does lack on the HP side but does give you a lot of torque and is quiet with no smoke like the coal rollers like. It might save you from the axle swap as well.Give Axis industries a call. They are one of the leaders in the 2.8 and will package the whole transmission and motor together and send you a drop in motor. You can look them up on instagram to see their swaps. I ran with cummings one day at Moab when they were testing the 2.8 before the release. I was impressed with how quiet it was and the fuel economy they were getting with it. Off road it just worked with the torque. Realisticlly you will be into it $15-20k A JKU on tons and 40's would be pusing the 2.8 IMO but if facatoy axles and up to 3'7's I think you would be fine.

Motech was going to offer the small Duramax motor as a JK swap, I never kept up on it to see if they actually did start doing those. May be worth a call. The 5.3 LS would work and likely not need tons.

There are also companies offering Tesla conversion in the $20k range so that would be another option.

Or you could take the $20k and buy another jeep. What shop in Reno is you Jeep at? My buddy has a shop in Sparks and does a lot of engine swaps.
 
#5 ·
I'd put a rebuilt 3.6 motor and transmission in it. 4bt's are noisy and while they have torque, not much power. Conversions are more expensive than most people think as you usually need to relocate a ton of stuff, and get things like the a/c to work, new driveshafts, motor mounts, etc. I did one on a different vehicle, it was expensive and time consuming.

You might look at a salvage site to find one you can pull the drivetrain from.
 
#7 ·
Gas to diesel is a no go in California. I would suggest giving Motech a call and do an LS swap. Most if not all of their swaps are California compliant. If you want to stay with a manual transmission I would suggest looking into the TR4050. It is only a 5 speed but with a 6.16:1 first gear crawling will be a breeze and it will handle 600 hp. Though when doing a LS swap with 6, 8 and 10 speed autos I would just swap.
 
#8 ·
I hate to harsh your mellow, but I would call a few salvage yards and see what is available for a used driveline. I can't imagine a low mile 3.6 & 6 speed costing more than 4k. You might be able to purchase a complete wrecked (or burned) JK from copart pretty reasonable and sell the extra stuff.

I purchased a 5.3ls, 4l60e with all accessories and wiring for $1100 ('05 driveline purchased in '16)
 
#11 ·
I'm with Shorthood. a quick search of LKQ had 3 engines from 2800-3400. and a bunch of transmissions from 1600 and up. that's the route I would go if I had to deal with emissions. but since I don't if and WHEN my 3.6 gives up it will either be a hemi or a LS....I'm a LS guy all day long but the hemi seems "easier" to keep everything working.
 
#14 ·
Sorry to hear about your misfortune as well,happy holidays even though looks like jeep owners continue to have engine problems like myself also,I just bought a 2014 jeep Wrangler unlimited sport and as soon as I cranked it up on the dealership lott I told the salesman I hear a knocking in the engine, sounds like lower crankshaft and the pully is wobbly some he said I don't hear anything and then the top lifters started chatering and I cut it off and I said go get your manager but after he restarted the engine it quot making the noise until I got it home and it started again and I called the dealership and the mechanic heard as I had him on the phone with me and he said stop the engine and then they sent a tow truck for it and I haven't seen it since October 17th its been 25 days now still in there shop.at champion Chrysler dodge jeep in gulfport ms.and the first breakdown just after driving it home on the interstate it breaks down and I told them I don't want it,they said it's got a 90 day warranty on it we will fix it.i did a review on the 3.7 engines and there junk in my book made with aluminum heads that when engine gets hot the aluminum melts bits and peaces if molted aluminum throughout the engine. Junk!
 
#15 ·
Mine also had rear main seal leak and dealership salesman Benjamin Barr tried to say the oil that's leaking down on the transmission part was from a recent oil change and I knew better than that and later on the engine starts making noise again after he wouldn't tell the salesmanager about it,now it's in the shop and I did tell the manager about it before I drove it off since he likes to hide major mechanical issues with what he sales there.Be very Cautious about buying from such a shady dealership. Bring a mechanic with you because it looks like they don't have one.my shit been in there shop for almost a month now and they want call you about it either to let you know what's going on.i've proved this message my name is Michael Brumfield pissed off in America with Dodge products.