It Cant be this simple? 4l60e np242

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willg719
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It Cant be this simple? 4l60e np242

Post by willg719 »

Good day everyone!

I am a long time lurker of the site. Been a Jeep guy since Highschool. Fell in love with FSJ few years ago but i just purchased my first J10s. $1700 for a complete 82 j10 with seized 304 (yup) and a 85 j10 with immaculate cab and rolling frame. I am feeling pretty lucky. Since nothing matches anyways I am going to build out a daily driver with lm7 from a 01 silverado I bought a while back.

I live in northern Saskatchewan. The truck will need to be able to drive well in all types of conditions. I want to run a NP242 selec-trac transfer case. i know it was run behind v8 in the dodge dakota and grand cherokee. it can handle it

Reading forums i see the following options

1. Buy adapter kit to swap 23 spline output into 4l60e transmission
2. Buy adapter kit to swap 27 spline input and relocate vss to transmission-transfer case adapter

Is there a 3rd much cheaper option?

The np246 that comes on my 4l60e is 6 bolt that looks identical to the np242j 6 bolt.
Buy 27 spline input from advanced adapters Jeep NP231 27 Spline long Input Gear (#716203). NP231 and NP242 share input gear.
The XJ np242 can be used with cable speedo. use Dakota digital Speedometer 8K Pulse Generator to get vss signal to my 4l60e and retain cable driven stock speedo.

If the above works i can avoid swapping my gauge cluster and save a bunch on mounting at same time.

It can't be that simple. I am missing something. Can someone please poke some holes in my theory.
Need to stop thinking about this and just buy a kit and be done with it.

Thanks,
Will
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Stuka
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Re: It Cant be this simple? 4l60e np242

Post by Stuka »

They were also offered in Hummer H1s in an HD variant which had a stronger differential. But these are not 27 spline either.

You could go for an NP246, which is the full time case found in Tahoe's and the like. But its electronically shifted. So you will need to worry about that, which does complicate things a bit. Its not as simple as the mechanical shifter in the 242. And I am not sure if the electric motor is wanting a signal from the PCM in order to shift. Also, these t-cases are kind of known for going through clutches because everybody just drives them in auto mode. Oh, and of course it does not use an analog speedo cable.

As for using 231 parts in the 242, I am not sure if that would work. I have never had them torn down side by side. But if it did work, that would be pretty cool.
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Pevious Jeeps: 1981 J10, 1975 Cherokee, 2008 JK, 2005 KJ, 1989 XJ

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willg719
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Re: It Cant be this simple? 4l60e np242

Post by willg719 »

Stuka,
Thanks for the quick reply. The NP242 that was in Hummer did not allow for 2WD from what i have read. It is 32 spline so we are back to swapping shafts to make it work.

I have 2 246 sitting on shelf but decided against going that route as i don't want any more electronics than necessary. (keep it simple stupid)

I have been playing with idea of using NP241c as many other LS Swap guys have done but i know i wont be happy unless i build my dream truck the way i want. So the NP242 is going in the truck one way or another. haha. The question is how!

According to my research both the input shaft and the speedo sensors from NP231 and NP242 are interchangeable.

I keep thinking to myself. " i can not be smarter than engineers that build this stuff. The kits have to be built a specific way for a reason"
I may end up just trying to put all this together and see what happens.

Until then if anyone else has comments on how to mate my 4l60e (2003 silverado) and NP242 (not purchased yet) please let me know

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willg719
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Re: It Cant be this simple? 4l60e np242

Post by willg719 »

Just in case anyone was interested. I found out that the Chevy new process transfer cases are rotated 90 degrees different than Jeep/Dodge.
A clocking ring can only change that 30 degrees.

This means if I want np242 I am paying for the full kit from advanced adapters or novak.

Hate to say it but i think im going with NP241c. They are cheap, readily available, easy to install and seems most people use these with swap.

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Re: It Cant be this simple? 4l60e np242

Post by 80Limited »

willg719 wrote: Tue Mar 16, 2021 10:09 pm Just in case anyone was interested. I found out that the Chevy new process transfer cases are rotated 90 degrees different than Jeep/Dodge.
A clocking ring can only change that 30 degrees.
Which case are you talking about? I would assume that pertains to passenger drop not driver drop cases.

Since I don’t know how my AW4 is going to react with my 5.3 dbw. I have been kicking around the same idea also, with a 4l60e or 80e to a np231j. From what I’ve read and tried to comprehend is that the transfer case needs proper spline tooth size, length and engagement and that the Jeep case needs to be clocked down with a ring.
What I was looking to do for a 4l60e was to get a 27 spline t-case input (short, medium or long) that would work with a cheap 3/8” driver side drop clocking ring. The same would apply to the 4l80e but would need a 32 spline.

I would like to hope this is a $200 solution rather a $600-$700 one.
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Re: It Cant be this simple? 4l60e np242

Post by Stuka »

willg719 wrote: Tue Mar 16, 2021 10:09 pm Just in case anyone was interested. I found out that the Chevy new process transfer cases are rotated 90 degrees different than Jeep/Dodge.
A clocking ring can only change that 30 degrees.

This means if I want np242 I am paying for the full kit from advanced adapters or novak.

Hate to say it but i think im going with NP241c. They are cheap, readily available, easy to install and seems most people use these with swap.
I don't think you mean 90, as that would mean one of them would be facing straight down, while another was flat. But much of the GM stuff is passenger side drop. While your Jeep is driver side drop.
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jpswapmohn
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Re: It Cant be this simple? 4l60e np242

Post by jpswapmohn »

I used the Novak adapter in a '95 4L60e to originally mate to the 229. Later, I swapped in a 242 and didn't have to change anything. I do not know what may have changed internally to the 4L60. I know mine is a 1-piece case and specific to late 94-96. I did upgrade the 242 with the Tom Woods SYE and 32-spline shaft during the rebuild. Not sure if this helps your cause, just tossing it out there.
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Laredo Matt
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Re: It Cant be this simple? 4l60e np242

Post by Laredo Matt »

***Disclaimer**** - just sharing a little information I have. I'm learning as I go and in no way an expert on anything. Just read a lot and learning by mistake when I get ahead of myself.

I recently purchased a Laredo that had an LM7 + 4L60e swapped already. Select-trac and NP 229 transfer case.

Image

as she sits now after starting the tear down two months ago. Focused mostly on body work / patches and modifications right now as I have limited time with a rotisserie and want to take full advantage of that.

Image


Image

I looked at the parts list the PO provided and the transmission adapter kit # listed is a part number for an RPM extreme kit. Similar in price ~$700 so no break there. Just another option for a kit if you do decide to buy the full kit. I can't compare ease of install or size benefits vs others kits but you can take a look for yourself if you go that route. Their website doesn't identify the 229 as one of the NP cases it works with but they do list the 242. I guess that means the 229 and 242 use the same kit like jpswapmohn suggested.

http://www.rpmextreme.com/Product/198/4 ... apter.aspx

I'm actually going to be pulling my engine / trans to upgrade. I have zero history on it and am planning for this to be my daily driver so I want a warranty and known good drive train. I'm gonna rewire, paint and upgrade the interior so I don't want to have to be messing around with a tired engine down the road. If I'm ever gonna do it, now is the time.

I'm leaning to a new/re-manufactured LM7 with with higher flow heads and a mild cam. Regardless, I'll need to get a new transmission (rebuilt, looking at monster transmission) to handle the power. The current engine/transmission combo was pulled from an 04 Sillverado and is the transmission is rated at 380 hp i think and I'm looking at closer to 400 at the wheel.

I'm months away from getting the frame / suspension cleaned up and having to worry about the swap but am spending a lot (too much perhaps) time thinking about it.

Stuka - you mentioned the NP246 as an all electric option but that it had its own issues. Anyone here done that swap or have an threads you recommend I read? Unlike willg, I'm looking to do a restomod with more updated drivetrain and conveniences while keeping the classic styling. I plan to make it my daily driver for the next 20 years.
Matt
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L8T 6.6L, 6L90
GEN III LS Swap (LM7 block)
4L60E

Topic author
willg719
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Re: It Cant be this simple? 4l60e np242

Post by willg719 »

Hey Everyone thanks for your comments and information! Since my last message a lot has changed.
I finally picked up one of my jeeps (9 hour round trip). Im in process of disassembly now.
A lot has changed with my project, i am going to start a build thread shortly.

I had recently purchased a NP261 because it mounts to 4l60e t-case natively and is manual shifting. Since the J10 has 8 foot box i wasn't too concerned about using slip yoke drive shaft. I had accepted i wouldn't be using a NP242....until now!

While i was looking at my 85 J10 pioneer last week i noticed it had selec-trac from factory. Its a sign!!
Talking to the current owner it rolled off line with 6 cylinder selec trac with 2.72 gearing.
I don't think that thing was making any speed records but i bet it stuck to the road like glue.

I found a low km NP242 from local wrecker with only 128k kilometers on it. $300 shipped to my door.

80 Limited keep me updated with your progress and ill do the same. ...

Topic author
willg719
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Re: It Cant be this simple? 4l60e np242

Post by willg719 »

oh and thanks laredo matt for info on your rig! nice to see someone running something remotely similar. I am probably going with transfer case adapter swap instead of transmission. I think your setup would probably be more reliable but my tranny was just rebuilt.
Also, none of your pictures loaded proper. Anyone else have that issue?

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Re: It Cant be this simple? 4l60e np242

Post by sirrus »

willg719 wrote:Also, none of your pictures loaded proper. Anyone else have that issue?
That seems to be a problem with google photos - it doesn’t give a direct link you can use on the forums. Better to use something else (I prefer Imgur or Tapatalk app) or resize and upload your pics on the forum directly
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Stuka
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Re: It Cant be this simple? 4l60e np242

Post by Stuka »

Its because google images isn't truly a public photo hosts. You need to have a google account to see them, even if they are set to 'public' :(
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