Rock-Trac Transfercase Swap?

Kugellager · **Posted:** Sat Mar 31, 2007 12:46 pm

Ok I was just wondering if this is a direct bolt up for our NV231/NP231 transfer case?

Quote:

It is designed as a bolt-in replacement for 23 spline NP231J cases

Is our case the 23 spline or the 21 spline?

Rock-Trac Transfercase 4:1 - Several places have it for this price.

If this is a direct bolt-in can our front/rear differentials and axels handle the extra torque that this will put out?

This would give those of us with a 6-speed manual transmission a 63.3:1 crawl ration!

John
];')

spoonplugger1 · **Posted:** Sat Mar 31, 2007 1:00 pm

Torque won't change, the axles are on the good side of the battle here.

jason thompson · **Posted:** Sat Mar 31, 2007 1:40 pm

with that you may need a new front DS and will need a new rear
You may be able to have the front retubed but you will need a rear DS with a slip joint

If you are going to go through all that trouble you could spend 1/2 as much an go with a tera low conversion
it should work in the 231 case but you will still need a hew rear DS
You could get the front from a XJ and retube ,that is what I have out back of the TJ and lucky me the front and rear use the same U-joints
This is what I am thinking of doing to the KJ but that will be later in life

Neatus · **Posted:** Sat Mar 31, 2007 3:55 pm

The front drive shaft on the KJ has CV joints instead of U Joints....so I would replace it anyway with one with U Joints unless you like to pay 500 bucks everytime you have problems with the front shaft.

tjkj2002 · **Posted:** Sat Mar 31, 2007 5:33 pm

Kugellager wrote:

Ok I was just wondering if this is a direct bolt up for our NV231/NP231 transfer case?

Quote:

It is designed as a bolt-in replacement for 23 spline NP231J cases

Is our case the 23 spline or the 21 spline?

Rock-Trac Transfercase 4:1 - Several places have it for this price.

If this is a direct bolt-in can our front/rear differentials and axels handle the extra torque that this will put out?

This would give those of us with a 6-speed manual transmission a 63.3:1 crawl ration!

John
];')

Our cases are 23 spline,It will work in our KJ's,need to have new drive shafts made though.1 ton tranfer case in a itty bitty Jeep :lol:

,I love it!

chefdab · **Posted:** Sat Mar 31, 2007 7:12 pm

Come on go for it! I've been waiting to see somebody actually do this swap..

tjkj2002 · **Posted:** Sat Mar 31, 2007 7:59 pm

chefdab wrote:

Come on go for it! I've been waiting to see somebody actually do this swap..

There is already a KJ with one in it,Allyrand's.

JJsTJ · **Posted:** Sat Mar 31, 2007 10:55 pm

OT, but I just got my shaft and yoke to put mine (241OR) into my XJ. I have a feeling that it might eventually land in the KJ but only after I beat up on it in the XJ first. (really wanted in the xj for the Rubicon trip)

You need to replace the balancer style rear shaft mount and use a yoke on the back side (not sure if it uses that same balancer style on the Auto Rubis?) and then a cv style driveshaft front & rear. I got the yoke from JE REEL, #2-4-5341-10R, $65 and CV shaft runs about $300.

tjkj2002 · **Posted:** Sat Mar 31, 2007 11:27 pm

JJsKJ wrote:

OT, but I just got my shaft and yoke to put mine (241OR) into my XJ. I have a feeling that it might eventually land in the KJ but only after I beat up on it in the XJ first. (really wanted in the xj for the Rubicon trip)

You need to replace the balancer style rear shaft mount and use a yoke on the back side (not sure if it uses that same balancer style on the Auto Rubis?) and then a cv style driveshaft front & rear. I got the yoke from JE REEL, #2-4-5341-10R, $65 and CV shaft runs about $300.

You can actually use the same style yoke that is on the front for the rear,they are both 32 spline outputs,seen a artical that showed it works.http://www.jbconversions.com/pages/reviews/showpage.php?m=4wor&i=2004.07_n2&p=2

JJsTJ · **Posted:** Sun Apr 01, 2007 12:12 am

tjkj2002 wrote:

JJsKJ wrote:

OT, but I just got my shaft and yoke to put mine (241OR) into my XJ. I have a feeling that it might eventually land in the KJ but only after I beat up on it in the XJ first. (really wanted in the xj for the Rubicon trip)

You need to replace the balancer style rear shaft mount and use a yoke on the back side (not sure if it uses that same balancer style on the Auto Rubis?) and then a cv style driveshaft front & rear. I got the yoke from JE REEL, #2-4-5341-10R, $65 and CV shaft runs about $300.

You can actually use the same style yoke that is on the front for the rear,they are both 32 spline outputs,seen a artical that showed it works.http://www.jbconversions.com/pages/reviews/showpage.php?m=4wor&i=2004.07_n2&p=2

Yes, correct. the one I got is basically the same and has a seal protector installed on it. I had to buy it from somewhere and I was ordering a new front shaft for the XJ from JE REEL so I had them throw it in the box. :wink:

Kugellager · **Posted:** Sun Apr 01, 2007 4:51 pm

When a L.O.S.T member finally does do this swap they need to do a good tech write-up with photos and a parts list...especially a parts list.

It will be great to see how it performs.

This is something I too would like to do with my manual at some point...Those of us with a manual already have a better crawl ratio than all you auto tranny guys...Actually wondering if it might be too much as on flat-smooth parts of the trail I already shift into 3rd and occasionally 4th gear as it is.

John
];')

chefdab · **Posted:** Sun Apr 01, 2007 5:34 pm

tjkj2002 wrote:

chefdab wrote:

Come on go for it! I've been waiting to see somebody actually do this swap..

There is already a KJ with one in it,Allyrand's.

I was referring to someone with a KJ that was still IFS but wanted the better crawl ratio. Allyrand's KJ is a little more of a one off type thing. I was thinking of something the masses could do.

Rock-Trac Transfercase Swap?

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