Motor and transmission swap

[JeepEV]

Hi folks,

I have a 2003 KJ that has a stuffed 3.7 motor, but otherwise a good car. I am looking at swapping the motor out for something *very* not Jeep, and I want to make sure I know what I am in for before I start.

The first part of my plan is to swap out the 42RLE auto with a NV3550 manual out of a 2.5L diesel KJ. A few questions.
- Has anyone done this swap before, or know of what I need to look out for?
- Will the manual transmission bolt up to my Selec-Trac transfer case?
- Should I consider swapping the transfer case to the Command-Trac that is currently bolted up?
- If I keep my transfer case, will I be able to use my existing drive shafts (ie, does the transmission move forward/back in the tunnel)?

The slightly more complex part of this project is the new motor. I don't have a problem with mating it up to the new manual transmission, and everything from the flywheel back will be stock Jeep. I also don't have a problem with making it turn, as I will be using custom electronics that I understand very well. What I am unsure about is what I may need to do to trick the Jeep computer into thinking everything is awesome so I can retain safety features like the ABS, airbags, etc. Can I simply remove the Jeep engine computer altogether?

This is sure to be a fun project, even if it is a little nuts. Hopefully the brains trust of this forum can help me avoid the biggest issues before I start.

Thanks in advance.

- Alex

 

[Billwill]

Have you asked your questions on the Ausie forum www.ausjeepoffroad.com ?

I know that there are several problems pulling out a 3.7 gasser motor and putting back a 2.5/2.8 CRD motor...cradle is different and some changes to the suspension and the wiring harness is completely different. ECM would have to replace the current PCM.

I have a 2002 Export Manual 2.5 CRD Sport with the Command Trac transfer case and Trac Loc 4.10 diff at rear. I did look into changing to the Select Trac transfer case some years ago and the information I received then was that it would not be a problem.

I really think Ausjeep will be the only site that could advise you unless some UK member here can chirp in!

 

[JeepEV]

Thanks for the info on the transfer case, and the Australian forum Billwill.

I'm not concerned about making the new motor turn (I've got that covered), and what I have in mind was never in *any* Jeep. What I am asking is mainly about the auto to manual swap, and if anyone has experience with the Jeep electrics when running a non-standard engine.

 

[Jay Tyrrell]

Hi folks,

I have a 2003 KJ that has a stuffed 3.7 motor, but otherwise a good car. I am looking at swapping the motor out for something *very* not Jeep, and I want to make sure I know what I am in for before I start.

The first part of my plan is to swap out the 42RLE auto with a NV3550 manual out of a 2.5L diesel KJ. A few questions.
- Has anyone done this swap before, or know of what I need to look out for?
- Will the manual transmission bolt up to my Selec-Trac transfer case?
- Should I consider swapping the transfer case to the Command-Trac that is currently bolted up?
- If I keep my transfer case, will I be able to use my existing drive shafts (ie, does the transmission move forward/back in the tunnel)?

The slightly more complex part of this project is the new motor. I don't have a problem with mating it up to the new manual transmission, and everything from the flywheel back will be stock Jeep. I also don't have a problem with making it turn, as I will be using custom electronics that I understand very well. What I am unsure about is what I may need to do to trick the Jeep computer into thinking everything is awesome so I can retain safety features like the ABS, airbags, etc. Can I simply remove the Jeep engine computer altogether?

This is sure to be a fun project, even if it is a little nuts. Hopefully the brains trust of this forum can help me avoid the biggest issues before I start.

Thanks in advance.

- Alex

Motor swap is an awesome idea! Now I can't speak to the ways and means but I have come to own a 2002 Jeep Liberty with a Jetta TDI Motor in it. Here is the built thread on it to give you some idea that where you are going has been done before.

Jeep Liberty TDI Conversion - TDIClub Forums

Jay

 

[JeepEV]

Wow. Thanks Jay.

That is *really* useful.

 

[Billwill]

Wow. Thanks Jay.

That is *really* useful.

Yes that is a very good link....a lot of work and maybe the KJ is too heavy for a 1.9 TDI though. If 4X4 was not a concern.....I seldom use mine...I would save weight by removing the transfer case, front diff etc.

I am happy with my 2002 Export 2.5 manual CRD....would not say no to the more powerful 2.8 with a six speed manual gearbox but my old 2.5 is a lot less complex than the later models ie. I have fixed vane turbo, 11 volt glow plugs etc. which means much less complex electronics which are prone to create problems.

Would prefer to have disks at the rear which came out later and ABS for safety reasons but that is not going to happen!

 

[JasonJ]

Wow. Thanks Jay.

That is *really* useful.

Not sure if sarcastic, or....

Hi folks,

I have a 2003 KJ that has a stuffed 3.7 motor, but otherwise a good car. I am looking at swapping the motor out for something *very* not Jeep, and I want to make sure I know what I am in for before I start.

The first part of my plan is to swap out the 42RLE auto with a NV3550 manual out of a 2.5L diesel KJ. A few questions.
- Has anyone done this swap before, or know of what I need to look out for?
- Will the manual transmission bolt up to my Selec-Trac transfer case?
- Should I consider swapping the transfer case to the Command-Trac that is currently bolted up?
- If I keep my transfer case, will I be able to use my existing drive shafts (ie, does the transmission move forward/back in the tunnel)?

The slightly more complex part of this project is the new motor. I don't have a problem with mating it up to the new manual transmission, and everything from the flywheel back will be stock Jeep. I also don't have a problem with making it turn, as I will be using custom electronics that I understand very well. What I am unsure about is what I may need to do to trick the Jeep computer into thinking everything is awesome so I can retain safety features like the ABS, airbags, etc. Can I simply remove the Jeep engine computer altogether?

This is sure to be a fun project, even if it is a little nuts. Hopefully the brains trust of this forum can help me avoid the biggest issues before I start.

Thanks in advance.

- Alex

Nicely done, Alex. Glad that you got it finished and it actually works. We see a lot of people on this forum whose first post is wanting to do some ridiculous engine swap and the extent of their ability to do so is only their imagination, no actual skills required to see it through.

An ALH swap doesn't seem to make sense, until it does. lol. I spent 4 years at a VW/Audi dealership in the service dept, saw some wicked cool modded VW's, and a ton of suped up diesels and 1.8T's alike.

Yes that is a very good link....a lot of work and maybe the KJ is too heavy for a 1.9 TDI though. If 4X4 was not a concern.....I seldom use mine...I would save weight by removing the transfer case, front diff etc.

I am happy with my 2002 Export 2.5 manual CRD....would not say no to the more powerful 2.8 with a six speed manual gearbox but my old 2.5 is a lot less complex than the later models ie. I have fixed vane turbo, 11 volt glow plugs etc. which means much less complex electronics which are prone to create problems.

Would prefer to have disks at the rear which came out later and ABS for safety reasons but that is not going to happen!

Yeah I wish Jeep had kept on the CRD model and refined it more over the years, and produced more of it, but diesel demand in the US certainly was not on people's minds, especially not in a Jeep.

I kinda want one though....

 

[JeepEV]

There is absolutely no sarcasm there and I am sorry if it came across that way.

That thread is very detailed and useful.

I am only at the start of my project, but it will happen.

 

[Jay Tyrrell]

Wow. Thanks Jay.

np!

That is *really* useful.

Yes that is a very good link....a lot of work and maybe the KJ is too heavy for a 1.9 TDI though. If 4X4 was not a concern.....I seldom use mine...I would save weight by removing the transfer case, front diff etc.

I am happy with my 2002 Export 2.5 manual CRD....would not say no to the more powerful 2.8 with a six speed manual gearbox but my old 2.5 is a lot less complex than the later models ie. I have fixed vane turbo, 11 volt glow plugs etc. which means much less complex electronics which are prone to create problems.

Would prefer to have disks at the rear which came out later and ABS for safety reasons but that is not going to happen!

Billwill this KJ still has the transfercase and has a 6 speed manual. 4x4 works like a charm and will crawl up almost anything. Also will run down the highway at 120kph too. It has the larger passat turbo and larger diesel injectors.

 

[JasonJ]

There is absolutely no sarcasm there and I am sorry if it came across that way.

That thread is very detailed and useful.

I am only at the start of my project, but it will happen.

OK, wasn't sure.. the asterisks threw me off. In my head, reading it the tone was with a virtual eyeroll sort of sound to it.

But yes, it was VERY interesting with lots of info. I read through all 17 pages, despite the fact that I am never intending to swap my KJ's drivetrain for anything.

 

[Jay Tyrrell]

OK, wasn't sure.. the asterisks threw me off. In my head, reading it the tone was with a virtual eyeroll sort of sound to it.

But yes, it was VERY interesting with lots of info. I read through all 17 pages, despite the fact that I am never intending to swap my KJ's drivetrain for anything.

It is a fantastic swap JasonJ! I am just thrilled that i was able to purchase it from the original owner and builder. Currently I am trying to source rust free doors and replace the inner and outer rockers with good replacement and rust free parts.

Jay

 

[Myke]

Please keep us updated. We need more threads tackling large mods like this.