241OR Rock-Trac/Teraflex 2-Low/Novak Cable Shifter Install

[Seiler]

Part 1

Well, push came to shove and I decided it was time to ditch the 242, and upgrade to a different T-case. I wasn’t interested in hacking up my tunnel, or dropping more than $3000. With the help of DJ, I chose the NVG241OR Rock-Trac from JB Conversions. After a lengthy E-mail conversation (determining whether the case would have enough spline engagement between the trans output and the T-case input,) I had one brand new 241 with 1310 Yokes installed Front and Rear on its way via Fed-ex freight to me for a little over $2100. By the way, the folks over at JB are awesome. Customer service is great, and I couldn’t have asked for better service.

Few Pictures right out of the box:





oOoOohh Shiny

Anyway, I wanted to make sure I did this right. I didn’t want to get it up there, change my mind, and drop the case again. Ideally, lift it once and keep it up there for a while. This T-case weighs right around 100 lbs. It’s not easy when you don’t have the appropriate jack to hold it in place. My rig will be Daily Driven until I can afford another mode of transportation. This means I want the Speedo to work, and I want the 4 Wheel Drive Indicator Illumination to function properly as well. JB sells a wire/switch set to make the 4WD Indicator to work. These pieces are customized for the 241OR application.

For reference – There are 3 wires (on NP242 models, 2 on NP231) coming from the harness, to the connector.

Black/White – Full-Time signal
Black/Red – Part Time signal
Black – Ground Distribution



Word on the street is the 241OR has a bit of a sweet tooth, so I picked up some liquid candy for it.



Now. A case that’s designed to handle to power output from a Cummins Diesel Motor; Maximum Torque Capacity: 5,555 ft lbs vs. 1,885 ft lbs with the NV231, and 1,486 ft lbs with the NV242(; 4:1 crawl ratio; 32 spline output shafts; and a direct bolt up… Could it get any better? How about 4:1 2 Wheel Drive?




Yep. Teraflex now makes a 2-Low kit, for the TJ 241OR. That install will be covered in the next reply.

Scott

Note: Above numbers regarding Maximum Torque Capacity were referenced from Eric Zappe's (EricsXJ on ) book - "High-Performance Jeep CHEROKEE XJ Builder's Guide 1984-2001."

JB is an NVG aftermarket distributer, and buy these cases straight from the plant. The metal tags are not installed at the point at which they are purchased.

 

[Phil]

Time for an Atlas.

 

[BlueGerbil]

I´m watching this - my 241 from a JK is sitting in the garage, hope to get it under the rig this winter.

 

[stumpXJ]

I put one in my XJ a few months ago, they are nice units. I got mine rebuilt from Mantrans in Tallahassee. $850.00 bucks, and I picked it up. I dont understand how they can charge such a premium at JB? I got my yokes from Tom Woods for $180 bucks.

Your T-case looks reconditioned to me, not "new" from Jeep. It looks like the case was bead blasted (from the color, and the missing or bead blasted badge that's normally red), and probably rebuilt or at least gone through to make sure everything is up to par. Did they say it was "new"? I could be totally wrong, just curious.

The 2 wheel low kit is pretty cool, what was the cost on that?

One of the best/easiest (and cheapest if you look around) ways to get a string case, and 4:1! Bolts right in, although you will probably have to trim the transmission mount a little.

~James

 

[Seiler]

I put one in my XJ a few months ago, they are nice units. I got mine rebuilt from Mantrans in Tallahassee. $850.00 bucks, and I picked it up. I dont understand how they can charge such a premium at JB? I got my yokes from Tom Woods for $180 bucks.

Your T-case looks reconditioned to me, not "new" from Jeep. It looks like the case was bead blasted (from the color, and the missing or bead blasted badge that's normally red), and probably rebuilt or at least gone through to make sure everything is up to par. Did they say it was "new"?

The 2 wheel low kit is pretty cool, what was the cost on that?

One of the best/easiest (and cheapest if you look around) ways to get a string case, and 4:1! Bolts right in, although you will probably have to trim the transmission mount a little.

~James

I've got Part 2 coming here in a little bit. Should answer a few of your questions. It's hard to tell if it truly was "new" or not. It sure had a brand new look to it. The inside of the case was spotless as well. I can't answer that for sure :dunno:

The yokes from JB together, were only $120. $60 a yoke.

Tera 2-low ran a little more than $250. Also, I did have to trim the transmission mount slightly to get the T-case to fit. That'll come in Part 3

Scott

 

[stumpXJ]

Very cool...

This may be a dumb question, but what would you use 2 lo for? I think the kit is cool, but then I started thinking... why do I need that?

~James

 

[JeepFreak21]

Very cool...

This may be a dumb question, but what would you use 2 lo for? I think the kit is cool, but then I started thinking... why do I need that?

~James

Front digs, tight turns, drag racing in the mall parking lot

Billy

 

[badron]

Very cool...

This may be a dumb question, but what would you use 2 lo for? I think the kit is cool, but then I started thinking... why do I need that?

~James

Just the thing for saving the clutch when dragging that 7200 pound trailer up a bad hill on pot hole road.
LOTS of torque at low road and engine speeds.
By minimizing clutch slipping trying to keep torque up but road speed down it (2low) will pay for itself by just saving one clutch, pressure plate replacement.
With a heavy trailer, big tires and almost any gearing useful for the highway. 2 low is the best thing since trailer brakes.

 

[RCP Phx]

I put one in my XJ a few months ago, they are nice units. I got mine rebuilt from Mantrans in Tallahassee. $850.00 bucks, and I picked it up. I dont understand how they can charge such a premium at JB? I got my yokes from Tom Woods for $180 bucks.

Your T-case looks reconditioned to me, not "new" from Jeep. It looks like the case was bead blasted (from the color, and the missing or bead blasted badge that's normally red), and probably rebuilt or at least gone through to make sure everything is up to par. Did they say it was "new"? I could be totally wrong, just curious.

The 2 wheel low kit is pretty cool, what was the cost on that?

One of the best/easiest (and cheapest if you look around) ways to get a string case, and 4:1! Bolts right in, although you will probably have to trim the transmission mount a little.

~James

They are brand new and do not come from Jeep.They are direct from New Venture!
Heres mine from 6yrs ago,notice the nice shiny sticker.

 

[Jes]

Front digs, tight turns, drag racing in the mall parking lot

Billy

You can't do front digs if ya have a bike chain in your transfer case.

 

[jeepme]

2low is great when you have a non selectable locker up front. It takes all the stress off the front end when turning in a tight spot and you would be amazed at how much you can do in 2wheel low on a trail. It really reduces the stress on steering and your front end. I use mine all the time with my aussie up front, well worth the money!!!!

 

[stumpXJ]

They are brand new and do not come from Jeep.They are direct from New Venture!
Heres mine from 6yrs ago,notice the nice shiny sticker.

Lol...mine has a 'shiny' sticker as well, but it was reconditioned. I guess what struck me as odd on the OP's tcase was the lack of sticker, and the red model plate if it was being billed as new. Doesnt really make any difference in the long run if it works like it should, I was just curious. especially at the huge price difference from a good used unit.

I can understand using 2 lo while pulling a heavy load up a hill, that makes sense. 2lo on the trail, I suppose that would be a good thing as well. Would be cool to try out...

~James

 

[256offroad]

Lol...mine has a 'shiny' sticker as well, but it was reconditioned. I guess what struck me as odd on the OP's tcase was the lack of sticker, and the red model plate if it was being billed as new. Doesnt really make any difference in the long run if it works like it should, I was just curious. especially at the huge price difference from a good used unit.

I can understand using 2 lo while pulling a heavy load up a hill, that makes sense. 2lo on the trail, I suppose that would be a good thing as well. Would be cool to try out...

~James

you have no idea how bad i want 2low.... but i am just going to live with my stock np231 for now...


cool build this has got me thinking!


WHERES THE REST?

 

[Seiler]

Very cool...

This may be a dumb question, but what would you use 2 lo for? I think the kit is cool, but then I started thinking... why do I need that?

~James

I have a really steep driveway, on somedays it can be a real challenge to climb that 5" curb......

WHERES THE REST?

Part 2 – This will mainly involve installation of 2-Low into the case. Part 2 has to be split into two, I had too many pictures.

Alright. First off, I can’t say I was hot on the idea of cracking open my brand new T-case and yanking everything out just to replace a small piece at the bottom. However, DJ badgered me into picking this piece up. $250 and 1 week later, I had a small white box waiting for me on a brown UPS truck. I work for UPS, so I can just jump on the truck before it leaves the hub and pickup my own stuff before 8am every morning.

Unfortunately, the only copy of installation instructions I could find were in reference to the JK Wrangler Rubicon. From what I was able to dig up, there are a few differences between the TJ Rubicon 241’s, and the JK Rubicon 241’s.

-Different bolt patterns holding the two case halves together
-The output / input shafts differ
-Speedometer housing / tailcone. TJ 241 has an electronic Speedometer in the tailcone, whereas the JK 241 has something else

I’m not exactly sure what the JK 241 uses to report speed to the computer, mostly because I don’t have access to one. BlueGerbil – If you could chime in on this, maybe snap a picture or two, I would greatly appreciate it.

Moving on, I’ll attempt to document the procedure I followed, for future reference to anyone planning this modification. I’m going to assume the T-case is already removed from the vehicle, and comfortably resting on a work bench / garage floor.

-Mark front and rear yoke orientation, in relation to the output shafts.
-Remove front and rear yokes (or, if you have a T-case with a flange, remove flange).




-Remove shift lever, detent plug (Assembled in 3 pieces – plug, spring and plunger), and Transfer Case Position Sensor.






-Remove the support for the Shift lever. This houses the seal, and bearing for the Shift Sector.



-Mark orientation, remove tailcone / speedometer housing.

OK, this is where you have to be careful. Inside the speedo housing, there is a tone ring. This is what sends the pulsing signal, to make everything work. In order for it to catch on the output shaft, it sits on a retaining pin. This retaining pin also sits in a small hole on the output shaft. When you remove the tone ring, make sure you handle that retaining pin carefully. Otherwise, it’ll fall out and you might never see it again.



I, like an idiot, forgot to take a picture of the tone ring and the inside of the speedo housing. It looks very similar to what's displayed in the image below (inbetween the mainshaft, and ESS speedo housing.



-Remove the 18 bolts holding the two case halves together, and pry apart.
-Don’t mess with the oil pump on the rear half. There’s a bolt holding it in place. You shouldn’t need to mess with it anyway. Loosening the bolts will ruin your day. Everything is aligned together.



Continued…

 

[Seiler]

Part 2.5

-Remove the two lock rings located on top of the front and rear sprockets.





-As a whole, remove the sprockets and chain. I brought the output shaft with me when I pulled mine. :dunce:



-Remove spring, and two retainers on top and bottom of spring. Remove shift rail. Remove output shaft mode fork and mode sleeve as a whole.




-Remove the hub and range fork as a whole.



-Lastly, remove the factory shift sector.




Here’s an image comparing the Teraflex 2-Low piece, to the factory piece. 2 Low is on the left, factory is on the right.



Install is the above steps, in reverse order. A few notes to take into consideration when re-assembling. It helps if you can shift the T-case into a 4WD setting. This will raise the output shaft slightly towards the rear of the case, thus making it easier to insert that retaining pin back in. When you do put the rear half back on, the output shaft has to fit through the splines on the oil pump. I had to pull and turn on the output shaft to accomplish this. This will raise the shaft the remaining length, so you can insert the retaining pin back in.

That should cover most of the Teraflex 2-Low install. I let my case sit for 24 hours or so, to allow the sealant to dry. I’ll post up Part 3 either later today, or tomorrow at some point.

Scott

 

[stumpXJ]

-Speedometer housing / tailcone. TJ 241 has an electronic Speedometer in the tailcone, whereas the JK 241 has something else

I know the JK uses a wheel speed sensor on the front axle. I also have a JK 241 case (non 4:1), and it will bolt right up to an XJ with no issues other than having no speedometer. Its basically a really beefy 231, with no speedo drive. The JK Rubicon 241 (with the 4:1) will work just the same as the TJ 241 in an XJ, except you wont have a speedo. The yokes interchange between the two as well.

Good write up on the 2 Lo kit, I may have to look into it the next time my tcase comes out (which I hope is no time soon...)

~James

 

[RCP Phx]

Great write up,let us know how it comes out!Also curious if this could work for the early cases?

 

[Fred]

When a trail is really steep, long, and really rocky, like most in CO, 2WD lo is the ticket. 4WD bounces one around twice as much, and generally isn't really needed, just the low range.

I only paid 1800 for my 241J from J+B conversions, lo these many years ago. Got the speedo connector from a Dodge dealer for 22, but he had to special order it. For the wheeling I do, it hasn't been especially a good investment. Sometimes it helps following someone with an auto, I drive a stick. It's good for pulling out fence posts, though.

Fred

 

[Seiler]

Part 3

In the process of installing my 2-low, I wanted to determine whether the speedo connector on the Jeep, and the one on the T-case would fit together without any issues. I still had the tailcone removed from the 241, so I walked it over to the Jeep and gave it a go. Nope. No luck. I snapped a few pictures of the different connectors.

T-case:




Jeep:



Well crud. At this point, I was under the impression I was almost done, and the 241 was almost ready to be mated with the transmission. I could cut the two connectors off, and solder the wires together? No, I want to be able to disconnect the two if I have to drop the T-case again.

I started looking around for a simple solution, but not too many presented themselves. By sheer accident, I stumbled upon a fitting on Teraflex’s website.



Link to product: http://www.teraflex.biz/products/connector-female-231ess-older.html

They make a female connector that works in conjunction with their ESS kit, for later model TJ’s. By looking at the picture, it appeared as though it would also connect to my 241 as well. Hell, for $13.99, it wasn’t going to hurt to try it out.




Fits perfect with the T-case. Nice and snug. Cool, onto the wiring.

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



Compared to the 3 on the new connector:
Brown: +5V
Blue: Sensor Ground
Black: Speed Sensor Signal

With all my bases covered, the T-case was finally ready to be installed. It went up just fine, a tad heavier than what I’m used to. No issues with fitting into the transmission tunnel, although it does sit very close to the tunnel. I did have an issue with my transmission mount. The plate present between the transmission, and the actual rubber mount has a lip on the edge, and contacts part of the T-case. Quick fix:




TBC...

Scott

 

[Seiler]

Part 4

Now installed -





The only item left to install was my Novak Shifter Assembly.





And the best part of it all:



Removal of the stock Z-gate assembly wasn’t difficult. Only tedious part I could have dealt without was pulling up the carpet in front of the driver’s seat to access the 4 bolts holding the linkage’s body floor plate. Novak supplies very detailed instructions with their kit, making install a breeze. I ran into one complication with mine. Teraflex supplies you with a new shift lever for their 2-low, which moves the point where the linkage connects, closer to the body of the case. This prevented the Novak Assembly from installing on the inside of the shift lever, per the instructions. Unfortunetly, the cable’s bearing end binds, prohibiting lever movement. I moved mine to the other side, which works fine. Shifting is still 100% better. I need to tweak / adjust the linkage further, but for the time being it’s ok.

You can see what I’m referring to in this first image:





After a few test drives, I’ve came to the conclusion my speedometer reads ~15% faster than what I’m actually going. I used my GPS to assist with finding actual speed. I have 4.88 gears, and 35 x 12.50 R 15 Mickey Thompson Baja Claws.

Again, with my rig being a daily driver, I want to know exactly how fast I’m going. I decided to order Superlift’s Truspeed Speed Sensor Recalibrator. It’s not cheap.



I’ll give ya’ll a heads up on how that works when I receive the unit and install it.

Thanks for looking!

Scott