04 LJ Ls swap with GM NP241C/4L60E

[mdbs14]

Needed now? Maybe not. But pretty necessary for any future mods. I wouldn't go without it if you have more than 3" lift. Even on a LJ. You could check if it binds at full droop if you like.

Have a 3" suspension lift.

 

[mdbs14]

Still haven't really heard the intended use. But for my relatively mild use of my LJ, a slip yoke would have to go.

I had to put an Atlas in mine to replace the boom-boomed 241OR. Had to sink the mount 1" through my tummy tuck skid. Which still puts it 3" above stock and that's only the small mount area - the rest is still 4" higher than stock. And needed to BFH the heck out of the tunnel. But it's tucked in pretty high and tight and never contacts the body.

And still running the lengthened factory non-CV shaft with no (drive shaft) vibes at 90 MPH.

- DAA

Post#14 street, and highway driving, no rock crawling, etc, nothing else

 

[mdbs14]

@mdbs14 depending on where you're at I believe when I sold my LS Swap blazer parts to @jpndave there was an early 27 spline gear in the parts bin. If it'll work with your 23J, he may, or may not, be using it in the future since that swap is getting a 6l80 as well.

I am north in MA

 

[mdbs14]

After some ready and calling around, here are what the numbers look like. please advise on what would make the most sense financially, and easier to run.

1) To run the gm np241c i already have, cost will be:
- $500 for JB Sye kit
- ~$100 for clocking ring (needed?)
(was hoping i didnt need all the above)

2) To run a jeep 231j from a friend out of 94 YJ 4cyl 5 speed:
- $150 for the Tcase (it already has the SYE installed)
- $600 Advance Adaptor tcase/tran adapter

3) To run the 231j I have on the 04 LJ
- $255 Sye kit
- $600 Adapter

Am open to other options.

Thanks

 

[glockman]

You know my opinion. Run the NP241C, install the SYE and the clocking ring. It is cheap, reliable and easy to replace if needed. You should add the cable shifter to run the 241 to your cost though. I think they are around $100 so the cost is pretty close for all three. My wife constantly stress tests the drivetrain on my LJ on 37's on the street. I've got about 15K miles on the swap now without any drivetrain issues.

 

[mdbs14]

You know my opinion. Run the NP241C, install the SYE and the clocking ring. It is cheap, reliable and easy to replace if needed. You should add the cable shifter to run the 241 to your cost though. I think they are around $100 so the cost is pretty close for all three. My wife constantly stress tests the drivetrain on my LJ on 37's on the street. I've got about 15K miles on the swap now without any drivetrain issues.

Which clocking ring is recommended? Where do I get the shifter cable?
Is this the right SYE from JB? Do I reuse the jeep steepdo sensor?

 

[Gravy]

You don't have to do the clocking ring IF you're ok with the cross member drop.

You'll need a cv rear driveshaft built with a SYE.
So pick a SYE with a 1310 cv yoke
or 1350 flange (so your driveshaft builder can build a cv off the yoke.)

Jeep uses a 1310 at the axle side. But 1350 is nice at the tcase side for a little more strength.

If you go 1310 at the tcase side you can take a xj, TJ, or zj front driveshaft to a driveline shop and they'll cut it down for less $. However the slip is a smaller diameter than some aftermarket slips and I've broken one driving like a dummy with a 4.0 so a V8 might be a good idea to have a bigger slip...

The nice thing about that SYE is you can use the stock LJ speedo drive.

 

[glockman]

Which clocking ring is recommended? Where do I get the shifter cable?
Is this the right SYE from JB? Do I reuse the jeep steepdo sensor?

I used the clocking ring Greg linked from Northwest fab.
For the SYE, I used the 1966 part with the flange but that caused more expense when I had the driveline made. I'd go with the 1941 part number for the reasons Gravy mentioned, plus it's cheaper.
I am using the Novak cable shifter even though they claim it won't work with an NP241C.

 

[mdbs14]

I used the clocking ring Greg linked from Northwest fab.
For the SYE, I used the 1966 part with the flange but that caused more expense when I had the driveline made. I'd go with the 1941 part number for the reasons Gravy mentioned, plus it's cheaper.
I am using the Novak cable shifter even though they claim it won't work with an NP241C.

You don't have to do the clocking ring IF you're ok with the cross member drop.

You'll need a cv rear driveshaft built with a SYE.
So pick a SYE with a 1310 cv yoke
or 1350 flange (so your driveshaft builder can build a cv off the yoke.)

Jeep uses a 1310 at the axle side. But 1350 is nice at the tcase side for a little more strength.

If you go 1310 at the tcase side you can take a xj, TJ, or zj front driveshaft to a driveline shop and they'll cut it down for less $. However the slip is a smaller diameter than some aftermarket slips and I've broken one driving like a dummy with a 4.0 so a V8 might be a good idea to have a bigger slip...

The nice thing about that SYE is you can use the stock LJ speedo drive.

Noted, and appreciate the input. on the 241c tcase front shaft, possible to reuse the front yoke on the 231 on the LJ? my front shaft length seem to be exact, however the double cardon joint on go on the 241c front yoke.

 

[Gravy]

You'll probably need to see if the 231j front 1310 cv yoke will fit the output spline count on the 241c. You might get lucky and be able to swap them. (Off the top of my head I want to say your 231j output is 27 spline?).
(It looks like the 241c yoke is a fixed yoke 1350 ujoint).

 

[mdbs14]

You'll probably need to see if the 231j front 1310 cv yoke will fit the output spline count on the 241c. You might get lucky and be able to swap them. (Off the top of my head I want to say your 231j output is 27 spline?).
(It looks like the 241c yoke is a fixed yoke 1350 ujoint).

I am hoping that the front yokes will be the same size

 

[mdbs14]

I am hoping that the front yokes will be the same size

Google AI says they are both 32 spline. ??

 

[mdbs14]

Do I replace this plug with the one on the 231j? I know the vss one will come from the 231j, not sure about the other.

Thanks and happy 4th

 

[UNSTUCK]

Does you stock tcase have the large round 4x4 sensor/switch? If so, I'm pretty sure you can't just swap it into that 241. The big round Jeep 4x4 switch isn't just on/off. It sends a different resistance value for each position the tcase is in. If you don't care about the 4x4 light on the dash or being able to use the lockers (rubicon?) without rewire then you can just keep the 241 switch in there. If that switch is a 4lo switch then keep it and run it to your ecm so it knows when you're in 4lo.

 

[mdbs14]

Does you stock tcase have the large round 4x4 sensor/switch? If so, I'm pretty sure you can't just swap it into that 241. The big round Jeep 4x4 switch isn't just on/off. It sends a different resistance value for each position the tcase is in. If you don't care about the 4x4 light on the dash or being able to use the lockers (rubicon?) without rewire then you can just keep the 241 switch in there. If that switch is a 4lo switch then keep it and run it to your ecm so it knows when you're in 4lo.

Yes the 231j has the same switch but with 2 wires, the one on the 241c has 3 wires.

 

[gijohn40]

if you are just going to drive this on road and never go off road why even worry about a transfer case?

 

[mdbs14]

if you are just going to drive this on road and never go off road why even worry about a transfer case?

Here north, we do get alot of snow and ice, so we do need the 4x4 everytime the weather is bad.

Am thinking maybe do the sye kit later.

 

[jpndave]

How do you plan on controlling the transmission? There are so many pieces to this problem that are being overlooked I can't list them all posting from my phone. @mdbs14 I'll send you a pm with my phone number. I can talk you through the issues and you can decide how to proceed.

 

[mdbs14]

I end up going with the 231j tcase due to it being smaller in size to fit with less mods.
I have the Advance adapter kit installed and a sye kit.
I have a few questions regarding the advance adapter tcase adapter.

1) The directions attached here says to make sure that the 27 spline output shaft is sticking out 4.5", mine is at about 5 1/4" but everything fit okay including the tcase.

2) should the reluctor ring sit all the way in to the end of the shaft or should it line up with the sensor?

3) the adapter mount has 2 ports for the sensor but only have 1, what do I do to the extra port on the side?

Thank you all

 

[jpndave]

I end up going with the 231j tcase due to it being smaller in size to fit with less mods.
I have the Advance adapter kit installed and a sye kit.
I have a few questions regarding the advance adapter tcase adapter.

1) The directions attached here says to make sure that the 27 spline output shaft is sticking out 4.5", mine is at about 5 1/4" but everything fit okay including the tcase.

2) should the reluctor ring sit all the way in to the end of the shaft or should it line up with the sensor?

3) the adapter mount has 2 ports for the sensor but only have 1, what do I do to the extra port on the side?

Thank you all

1) you need good engagement of the splines and no binding on the splines, case or shaft - no bottoming out. It should "float" there engaged on the shaft. You are probably fine but just watch for any binding. You could put grease on the shaft/gear and see where it witnesses to.
2) The reluctor should be centered on the sensor or close to it. Centered will give a stronger more consistent signal.
3) I am not familiar with that adapter specifically. The 4L60E speed sensor is not position sensitive, there is no location index. The extra hole might be to allow for clearance issues one side or the other. Is there a plug for the extra hole?