Swapping Rubicon transfer case into Sport

[SuspectLJ]

Hey everyone! it's my first post here so please forgive me if i inadvertently break any forum rules. i searched extensively through the forum to see if this question has already been an but i couldn't find an exact answer or maybe i'm just dumb and missed it.

A few months ago i purchased 2004 LJ 4.0/Automatic Sport and have been planning my build ever since using this forum as a guide.

a few weeks ago i was fortunate enough to find a 2004 TJR 4.0/Manual for sale near me for $3500. The body and frame were completely rotted out but i parted it out and made my money back while getting to keep the front and rear axles and transfer case.

I plan on swapping the axles and transfer case into my LJ but from what i've read on past threads is that the input shaft on the transfer case may need to be changed since it came from a manual jeep and would be going into an automatic.

Does anyone know if the input shaft would need to be changed on the NP241? I've seen conflicting information.

Any help would be greatly appreciated!

 

[Rickyd]

Hey everyone! it's my first post here so please forgive me if i inadvertently break any forum rules. i searched extensively through the forum to see if this question has already been an but i couldn't find an exact answer or maybe i'm just dumb and missed it.

A few months ago i purchased 2004 LJ 4.0/Automatic Sport and have been planning my build ever since using this forum as a guide.

a few weeks ago i was fortunate enough to find a 2004 TJR 4.0/Manual for sale near me for $3500. The body and frame were completely rotted out but i parted it out and made my money back while getting to keep the front and rear axles and transfer case.

I plan on swapping the axles and transfer case into my LJ but from what i've read on past threads is that the input shaft on the transfer case may need to be changed since it came from a manual jeep and would be going into an automatic.

Does anyone know if the input shaft would need to be changed on the NP241?

Any help would be greatly appreciated!

I don't think the inputs are a different spline. But i hope you have the shift linkage for the np241 and the electrical wiring for it. They are different.

 

[CMBD]

I love 4:1 low range. Its awesome. Just about everything I have ever built both auto and manual has had 4:1, but I also had 2:1 which is why it is awesome.

Just my two cents but...

I wouldn't want just 1:1 and 4:1 with an auto.

 

[SuspectLJ]

I don't think the inputs are a different spline. But i hope you have the shift linkage for the np241 and the electrical wiring for it. They are different.

I was more worried about the length of the input shaft, i think on the np231 the length of the shaft varies depending on the transmission type from what i've read.

I was thinking of buying the Savvy kit as that seems to be the most recommended.

Is the wiring only if you want 4wd light to work or is there more to it?

 

[SuspectLJ]

I love 4:1 low range. Its awesome. Just about everything I have ever built both auto and manual has had 4:1, but I also had 2:1 which is why it is awesome.

Just my two cents but...

I wouldn't want just 1:1 and 4:1 with an auto.

You would stay with the stock one?

 

[CMBD]

This is just me I will guarantee there are many differing opinions here.

But for what I do and where I go, I would with the auto. I would not trade 2.7 for 4:1 unless I could have both.

4:1 with an auto is way cool, but something in between 4H and 4:1 4L is needed. Because unless you have a full manual valve body, if 4H is too high to be useable, and 4:1 is too low, your committed.

But with a manual, just 4H and 4:1 4L would be great.

I don't get how people can enjoy doing rocks with a 5 speed and 2.7:1

 

[Rickyd]

I was more worried about the length of the input shaft, i think on the np231 the length of the shaft varies depending on the transmission type from what i've read.

I was thinking of buying the Savvy kit as that seems to be the most recommended.

Is the wiring only if you want 4wd light to work or is there more to it?

You could take the 231 off and compare?

@JMT @jjvw @Mike_H are the output seals for the nv3550 and the 42rle at the same depth?

 

[Mike_H]

I didn’t change anything in my transfer case when I swapped my manual for the auto.

 

[Mike_H]

This is just me I will guarantee there are many differing opinions here.

But for what I do and where I go, I would with the auto. I would not trade 2.7 for 4:1 unless I could have both.

4:1 with an auto is way cool, but something in between 4H and 4:1 4L is needed. Because unless you have a full manual valve body, if 4H is too high to be useable, and 4:1 is too low, your committed.

But with a manual, just 4H and 4:1 4L would be great.

I don't get how people can enjoy doing rocks with a 5 speed and 2.7:1

My experience is the exact opposite. I went from a manual with 4:1 tcase and always wanted something in-between 1:1 and 4:1. 4wd high was basically useless. The transmission ranges didn’t match up to the engine torque and it was either too high a gear (1 and 2) or too low and the Jeep couldn’t handle it.

With the auto 4 high is much more useable, since the torque converter will slip a bit. I still want to do a rubicrawler and a 2:1 atlas, but for now, I’m happy with my 4:1.

 

[mrblaine]

You could take the 231 off and compare?

@JMT @jjvw @Mike_H are the output seals for the nv3550 and the 42rle at the same depth?

The NV241OR is forward and backward compatible with all transmissions found behind the 4.0 from 03-06 with no changes to make it fit and not leak.

 

[psrivats]

I still want to do a rubicrawler and a 2:1 atlas, but for now, I’m happy with my 4:1.

I heard from reliable sources that there will be a certain orange jeep with that combo later this year. I wonder if you can go see/drive it?

 

[Mike_H]

I heard from reliable sources that there will be a certain orange jeep with that combo later this year. I wonder if you can go see/drive it?

Maybe someday!

 

[mrblaine]

Maybe someday!

Just get him to meet you halfway, somewhere about Iowa should do it.

 

[Mike_H]

Just get him to meet you halfway, somewhere about Iowa should do it.

Iowa will be a PERFECT place to test out a rig of that caliber!

 

[psrivats]

Iowa will be a PERFECT place to test out a rig of that caliber!

Mt Rushmore is almost halfway

 

[Apparition]

Mt Rushmore is almost halfway

Go for the Corn Palace

 

[SuspectLJ]

The NV241OR is forward and backward compatible with all transmissions found behind the 4.0 from 03-06 with no changes to make it fit and not leak.

I didn’t change anything in my transfer case when I swapped my manual for the auto.

You could take the 231 off and compare?

@JMT @jjvw @Mike_H are the output seals for the nv3550 and the 42rle at the same depth?

This is a huge relief! Thank you guys for the help i really appreciate it.