Rubicon RockTrac transfer case clarification (J vs OR)

Wife: what are you doing, its 8:30?

Me: I have to go crawl on the ground and take a picture of my transfer case.

Wife:........ok


So here you go, for science. Build April 03

20190722_085937.jpg
 
Currently rebuilding this case from an 06 LJ Rubicon. That 4:1 is impressively large. Interesting to note that the TJ manual has a breakdown for the 241 but they show 6 planetary in the diagrams. Had me scratching my head for a second. As far as I know the 241 is only present in TJs from 03-06 with the Rubicon package and the 4:1, so why it shows the six gear variant is strange.

[EDIT]
I don't know what I was talking about; the FSM definitely shows the 4-gear planetary. I was referencing multiple sources, including a rebuild breakdown for a 231, and I must've convoluted the two.
 
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Jlasall1 said:
Currently rebuilding this case from an 06 LJ Rubicon. That 4:1 is impressively large. Interesting to note that the TJ manual has a breakdown for the 241 but they show 6 planetary in the diagrams. Had me scratching my head for a second. As far as I know the 241 is only present in TJs from 03-06 with the Rubicon package and the 4:1, so why it slows the six gear variant is strange.
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How many gears are in the one you’re rebuilding?
 
Jlasall1 said:
Currently rebuilding this case from an 06 LJ Rubicon. That 4:1 is impressively large. Interesting to note that the TJ manual has a breakdown for the 241 but they show 6 planetary in the diagrams. Had me scratching my head for a second. As far as I know the 241 is only present in TJs from 03-06 with the Rubicon package and the 4:1, so why it slows the six gear variant is strange.
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Just did mine about 4 months ago. It was close enough to the FSM to get most all bearings, seals, and the chain replaced. I didn’t find any videos online that matched this T-Case’s internals. Also, there is one bearing that is pressed into a recess that all the online videos show being cut up to remove. I was able to remove mine with a steering wheel puller. Good luck rebuilding it.
Can I ask why you’re rebuilding it?
 
Find a thread on a damaged 241....unheard of . The 4:1 is just perfect in the rocks . It gets hooked up to a lot of bigger trucks and engines...it can handle a 4.0 TJ with ease .
 
AndyG said:
Find a thread on a damaged 241....unheard of . The 4:1 is just perfect in the rocks . It gets hooked up to a lot of bigger trucks and engines...it can handle a 4.0 TJ with ease .
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Yep. I didn’t find any signs of wear at all on any of the gears. My TJ is making an odd noise so I’m tracking it down. Thought it may have been warn/damaged nylon pads on the shift fork. Sadly, that wasn’t it. The hunt continues!
 
Ppd7207 said:
Just did mine about 4 months ago. It was close enough to the FSM to get most all bearings, seals, and the chain replaced. I didn’t find any videos online that matched this T-Case’s internals. Also, there is one bearing that is pressed into a recess that all the online videos show being cut up to remove. I was able to remove mine with a steering wheel puller. Good luck rebuilding it.
Can I ask why you’re rebuilding it?
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Rear shaft seal is bleeding ATF everywhere and my chain is slapping around inside the tcase due to slack. I'll remember the steering wheel puller suggestion, I'm sure it will come in handy.
 
Ppd7207 said:
Yep. I didn’t find any signs of wear at all on any of the gears. My TJ is making an odd noise so I’m tracking it down. Thought it may have been warn/damaged nylon pads on the shift fork. Sadly, that wasn’t it. The hunt continues!
Click to expand...
I'm actually into this job after replacing all u-joints on the front driveshaft to try and track down an unpleasant sound in 4WD. I'd check your chain; if it's able to double back on itself, it's too stretched and needs to be replaced. If it gets enough play in it, it will hang low enough to slap the transfer case housing.
 
Jlasall1 said:
I'm actually into this job after replacing all u-joints on the front driveshaft to try and track down an unpleasant sound in 4WD. I'd check your chain; if it's able to double back on itself, it's too stretched and needs to be replaced. If it gets enough play in it, it will hang low enough to slap the transfer case housing.
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I did replace the chain just in case when I had it open. I’ve posted info on the soundbefore, but here goes again.

It is a grinding-ish sound. Not like trying to put it in gear with the clutch out, but maybe like the edges of gears are just slightly touching.

Here’s when it happens:
While moving and the vehicle is out of gear in neutral.
When the clutch is pushed in and the stick is in gear.
Only in 2WD even in neutral in 4WD it doesn’t happen.
The sound comes from the t-case/transmission area, but hard to really pinpoint.

I have replaced the U-joints, and rebuilt the transfer case. Due to a bad throwout bearing, I also replaced the clutch, friction plate, fly wheel and the throwout bearing.

A transmission mechanic said it could be the transmission, but he wouldn’t bet his money on it.

The vehicle drives great with no there noticeable transmission problems noted.

Any suggestions would be helpful, as the current plan is to drive it until something explodes at which point, even I will be able to tell what the problem is.
 
jeep_boss said:
I thought that I had understood the nomenclature of the RockTrac t-cases, after reading a thread on the internet somewhere a while ago. I understand some of the history behind New Process (NP) New Venture (NV), New Venture Gear, but what I do not understand is the "J" designation on the t-case badge.

My understanding was the J's were 2.72:1 ratio and the "OR" is 4:1. My 05 TJR has a 4:1 t-case, which is also stated on the build sheet - yet, the badge says "241J". I read long ago that OR stood for Off-Road, and the 4:1 t-cases have "OR" and not "J".

See where I'm confused?

View attachment 39342
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I just saw this post and thought I would share a company’s name TNT Transfer case. Talk to a guy name Tim and gave his the number right under the 241J stamp. He entered in the number and it came back as a OR. My stamp says 241J and 4-1 on the tag. Anyway maybe this will help somebody else.
 
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