Ammo for the gear driven crowd

Picked up a Rubicon Rock-Trac transfer case last weekend. I am prepping it for install. You know things like pulling out the credit card for new yokes and driveline.

I think I got things figured out but really can't order drivelines without measurements. I guess this will be a couple week job.

Here's a couple of pictures of the box with the bike chain in it.







I will provide updates on the installation.:repair:

I'm way interested in this. Please keep it detailed.

Awesome! How much did you score the 241 for and from where?

If you had black steel wheels I would think less of you as a person but I am ok with the bicycle chain transfer case.

Phil said:

If you had black steel wheels I would think less of you as a person but I am ok with the bicycle chain transfer case.

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irate1: First I gotta get a job, then shiny rims, then I'll have Phil and Letterman's respect...

I bought the TC from a guy out of Fernly Nevada. Good deal, $600. Should be installed and complete for less than $1000 with a new rear shaft. A little more if I have length issues with the front shaft.

I will provide a detailed build including pt.#'s, pricing, issues and of course pictures.

Phil said:

If you had black steel wheels I would think less of you as a person but I am ok with the bicycle chain transfer case.

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The jeep in your avatar had black steel wheels on it when that photo was taken...

Yes, and I was less of a person then.

playwithit said:

I bought the TC from a guy out of Fernly Nevada. Good deal, $600.

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Damn you Kelly! Why didn't I know about this? I would have snatched it up in a second!

EricsXJ said:

Damn you Kelly! Why didn't I know about this? I would have snatched it up in a second!

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That i know you would have...

EricsXJ said:

Damn you Kelly! Why didn't I know about this? I would have snatched it up in a second!

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That's why I was quiet as a church mouse. I have been waiting a year for this deal.

Another guy on Pirate has one with Novak shifter and 1310 yokes. He's asking $900 delivered. Although he screwed me around when I tried to buy it previously listed at $800.

XJ_ranger said:

The jeep in your avatar had black steel wheels on it when that photo was taken...

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You know, that might be why he was the forgotton man on Fordyce years ago.

600$ for a 4:1 case is very good.

Bryan C. said:

You know, that might be why he was the forgotton man on Fordyce years ago.

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Straight swap my ass.assgas: Not too bad though. A few things left to do.

Here's the highlights so far.

Draining the old ATF.


One of the new Tom Woods 32 spline 1310 series CV Yokes. Strange, the orignal Rock Trac 1330 series yoke and flange had a 1.875" ground hub and the TW yokes are ground to 1.938. I found this when I remove the slingers from the Rubicon tc to install them on the replacement yokes and realized they don't fit. I spoke with Eric at Tom Woods about it and he stated they are ground to fit without the guards. I mentioned, I was worried about wear to the seals and yoke. Eric rebutted that the debris could get trapped behind the slinger and do more damage. I guess:dunno:

The front output yoke nut had a wee bit more than 160 ft. lbs. on it. Took three session with the PB Blaster, a little heat and a three foot cheater to get it off.

The rear output shaft was leaking between the splines and the flange we I received it. The install instructions called for cleaning the splines and then coating them with silicon when installed. Threadlocker was used and it was torqued to 160 lbs.

The front yoke couldn't be permanently installed until the shift lever was fitted. I decided to use the stock (231) shift lever turned upside down (more on that later). You can see the blockage caused by the yoke.


The 1996 XJ 4wd light switch won't work with the rubicon switch shown below.

The replacement was purchased through Amazon. Switch - Dorman 600-506. Pigtail - AC Delco PT724 (I returned this and modified the existing pigtail).

The speed sensor connector on my 241OR is just a straight three position weather pack connector. I bought a kit of these a few years ago.

So, I cut of the connector on the XJ and terminated a weather pack connector on the leads.

Seiler said:

The 3 wires on my Jeep are:
Violet/Orange: +5V
Black/Yellow: Sensor Ground
White/Orange: Speed Sensor Signal

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Thanks Scott
The Rock Trac Transfer case is:
Brown: +5V
Black: Ground
Orange: Speed Sensor Signal



The removal of the case was done without to many pics. I did the complete tear down alone. Transmission Cross member removed.


I had to remove the exhaust pipe at the exhaust manifold in order to reach the 6 - 9/16" nuts hold the transfer case to the transmission. Spent a good 45 minutes messing with those. Can you say cramp.

I was able to manhandle the 50 lb 231 out without help, but new it wasn't going to be that easy with the upgrade.

The shift lever on the 231 is pointed down.



On the Rubicon case it will need to point up for the shifter to show proper gear(If pointed down two high would be all the way back on the shifter).
Fast forward, NV241OR installed.

More in a minute. Need to go to market for beer.

Cont. shift linkage.

The lever needs to point up with the 4:1. If not, two high would require the shifter to be pulled all he way back. Using the 231 shift lever turned up, it almost makes contact with the case. So, I used the grinder on it taking just enough for clearance.


The shifter is adjusted with it in four low. You can see the adjustment bolt in the picture.

The transfer case is just larger all the way around. Here's a picture of the transmission mount that needed to be clearanced.

See the issue here with the mount loose.



Now, the problems yet to resolve.

The transfer case jacked into final position with transmission cross member installed creates a small issue or two. the tunnel under the drivers seat was massaged by me when I installed the Mastercraft seats. I must massage it again in the opposite direction as the case is sitting against the body (transmission tunnel).



Next in line is my transfer case skid. don't fit now. seems the 241OR hangs down just an inch or two more than the 231. I will either modify the one I have or replace it with a full belly. Probably both.



Last but not least, drive shaft. Rear needs to be 1 1/2" longer, yoke to yoke than the converted front shaft used with my hack n tap. I will order a Tom woods 33" shaft in the morning. Front shaft may be ok for now, but I have another 3/4" of shiny splines showing on an already taxed front shaft.

I need to fill the case with atf, I have 3 quarts of Mopar ATF+4 taking space on the shelf. I hear the case uses just over 2 quarts to fill.

I thinks that's all, if i missed anything feel free to ask. I want to thank a few people who assisted with previous threads here, Pirate, Jeep Forum and others.

This thread was the most help, thank you Seiler.
http://www.naxja.org/forum/showthread.php?t=1007897

http://www.pirate4x4.com/forum/showthread.php?t=566955
http://www.jeepforum.com/forum/f9/np241j-rock-trac-transfer-case-4wd-switch-revealed-651308/
http://www.virtualjeepclub.com/showthread.php?63478-NP231-to-NV241-SWAP-%28In-a-nut-shell%29
http://www.dana.com.br/ForadeEstrada/Produtos/pdf/J300P-4A.pdf

So rather than removing the transfer case to clearance. My hope is to remove crossmember and lower transmission enough to get a 1" socket between the transfer case and body and jack it back up to clearance the 2 spots where it makes contact. Think it will work?

The tc guard fits well now after a little adjustment. The new driveline is scheduled to arrive on Thursday. So test ride on Friday. If all is well, 4.88 gears will be installed on the weekend.