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Rock-Trac swap? +any other automatics fit a 4.0


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I know there was an article about swapping a rock-trac transfer case from a rubicon TJ Wrangler into a Cherokee. Would this same swap work in an MJ ? The New Venture 241J (NP241J or NVG241OR)case with a 4:1 low range built in seems like it would be a good deal if it would go in an MJ. The article was in the summer 2011 4X4 Garage magazine.

Does anyone know if there are any other auto. trans. that will fit a 4.0 6 cyl? Just wondering if any other models or makes have a 5 speed (or 6) auto trans that would bolt up to a 4.0?

 

Thanks,

Olddog

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Would have to be a tcase from 01 or older tj. Otherwise speedometer won't work. Any other direct fit autos are not worth even considering.

 

Rock Tracs where used in the Rubicons 03-06. I just reread the article in the 4x4 Garage Mag. It does not say what year jeep they are using just "any jeep cherokee with a 23 spline output shaft".

 

Talking about the speedo, they said the 3 wire input for the speedo worked for them also.

 

AW4 trans

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Just an FYI: The 241J and the 241OR are different t-cases. The 241J ( like the 241c and 241D) has a 2.72:1 low range and the external case lacks the re-enforcing ribs that are cast into the 241OR. The two are interchangeable and either will bolt directly to any transmission that accepted a 231J.

 

IIRC the 3.7 & 4.7 share the same small-block Mopar )3.7/4.7 powertech & 3.9/318/360/new Hemi) bell housing bolt pattern. If so none of the later Grand Chero 5 spd auto's will physically bolt to a 4.0 I6 which uses the AMC bolt pattern. I believe that the JK's 3.8 retained the FWD Chryco pattern and the trannies use a unique bolt pattern to match it but that does not match either the RWD Mopar or AMC (4.0 I6) pattern but I am not 100% sure. Part of my belief comes from the fact that the Nitro is available with the Mopar-patterned 3.7 and uses one tranny and the 4.0 V6 ( which shares the minivan roots and bolt pattern of the 3.3/3.8) uses another. :hmm:

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My mistake. I thought that the 241OR was tagged as such.

 

In that case there are two different 241J's and, besides the external webbing mentioned, the tag will say "2.72 ratio."

This shows the extra webbing of the 4.0:1 low range model:

Image Not Found

and this is the 2.72:1 low range model:

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My mistake. I thought that the 241OR was tagged as such.

 

In that case there are two different 241J's and, besides the external webbing mentioned, the tag will say "2.72 ratio."

This shows the extra webbing of the 4.0:1 low range model:

Image Not Found

 

Funny how I care more about the underside, mechanically and aesthetically, than the top side of a rig, and that one looks good.

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My 241J is a 4:1. I have no idea what it came out of although the PO told me it was a brand new never used replacement for a Rubicon. Could have come from a Liberty but I'm not sure.

 

4740400143_fba845f88c_b.jpg

 

Acording to the part number here, this is an 03-06 Rubicon T-case

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