Topic: Crawl Box?

[C.Redbeardd]

Anyone know much about building  a crawl box(dual transfer case) for the np231? Im interested in this mod, but cant find any good how to guides.

[aw12345]

Look on Pirate, a fellow sells a kit there to join 2 231 transfer cases together

[Bounty Hunter]

http://www.pirate4x4.com/articles/productreviews/mad_rooster

[sharpxmen]

http://www.pirate4x4.com/articles/productreviews/mad_rooster

Bounty,
is he still making these kits? And do you know if it works with the Rubicon t-case? Thanks in advance

[Bounty Hunter]

I have no idea, and 4:1 isn't deep enough for you?

Booty fab doubler: http://www.pirate4x4.com/forum/showthread.php?p=2983930&mode=threaded&highlight=doubler+np231

D.D. Machine was making a good 231/231 doubler that appeared better and cheaper than the MadRooster setup, but I can't find anything on it anymore.

[sharpxmen]

and 4:1 isn't deep enough for you?

i want to use the rubicon for the crawler box (i have a dana 300) - just so i get 3 different ratios

D.D. Machine was making a good 231/231 doubler that appeared better and cheaper than the MadRooster setup, but I can't find anything on it anymore.

he's gone, not sure if he still makes them, read some posts that he was hard to get hold of and nobody was able to get the kit anymore from him

[Jeffy]

i want to use the rubicon for the crawler box (i have a dana 300) - just so i get 3 different ratios

he's gone, not sure if he still makes them, read some posts that he was hard to get hold of and nobody was able to get the kit anymore from him

You'd be better off using the Rubicon NVG241OR as the transfer case and using the NVG231J as the crawler.

[oldjeep]

One of these?  I built a Box4Rocks when I originally built my YJ.  Even with the motor pushed forward 7" I didn't like the driveline length that I wound up with.

[Bounty Hunter]

What's the low ratio on a d300?  Using the 241OR may just get you a 4spd transfer case, but what a waste of an expensive Rubi box that would be.

[sharpxmen]

What's the low ratio on a d300?  Using the 241OR may just get you a 4spd transfer case, but what a waste of an expensive Rubi box that would be.

i believe it's 2.6:1 or something close to that. Just thinking about it as if I want to get a 4:1 kit for the 231 or the 300 would probably get the price to the same level as using the Rubi one which is a 4:1, and if you find one with the chain busted could be cheaper - i don't have a rubicon t-case laying around :)

EDIT: i also wonder if the reduction gear from the rubi t-case would fit in a plain 231 (could be larger diameter), I saw one with a broken case at some point, not sure if the wrecker has it still

[sharpxmen]

found this on e-bay - i believe it's 4x4 machine

http://cgi.ebay.com/ebaymotors/doubler-crawlbox-NP-231-box4rocks-kit-jeep-Klune-V_W0QQitemZ160375745537QQcmdZViewItemQQptZMotors_Car_Truck_Parts_Accessories?hash=item255723ac01

[FourbangerYJ]

found this on e-bay - i believe it's 4x4 machine

http://cgi.ebay.com/ebaymotors/doubler-crawlbox-NP-231-box4rocks-kit-jeep-Klune-V_W0QQitemZ160375745537QQcmdZViewItemQQptZMotors_Car_Truck_Parts_Accessories?hash=item255723ac01

It's from Duffy

Cut and paste from Ebay ad.


np 231 crawl box "doubler kit"

This is a simple kit that takes a np231 tranfer case and makes a low cost crawl box out of it, It uses the front half of a np231 case that you provide and in about a hour or so of work you can have a crawl box that will lower your gearing 2.73 to 1 . Just take a 231 case with the right input shaft to fit your trans output and pull it apart , lay the big plate on the casting and mark it were to cut, then file or grind the block off plate to fit, tig weld the block off plate and thats it The kit is made in house on CNC equipment out of 6061-T6 alum and the mid shaft is 4340 cromo steel thats been through hardened. Well I make these in lots of spline counts I only offer 23 spline kits on ebay, so you can mount a Dana 300 flipped or non flipped as the T case or use a second np231 as the T case. there is a lot of info on line under my shops name D.D.Machine and under the product name box4rocks. Thanks D.D.Machine

[FourbangerYJ]

I gotta say the easiest and shortest overall product is gonna be the Klune. But they are expensive compaired to the others. But good driveline angles have their value.

[oldjeep]

found this on e-bay - i believe it's 4x4 machine

http://cgi.ebay.com/ebaymotors/doubler-crawlbox-NP-231-box4rocks-kit-jeep-Klune-V_W0QQitemZ160375745537QQcmdZViewItemQQptZMotors_Car_Truck_Parts_Accessories?hash=item255723ac01

4x4machine.com is D&D - but their website is long gone.   Good kit, everything fit nicely - you do need to find someone to weld the aluminum cap plate in if you don't have aluminum welding capability.

[FourbangerYJ]

This Klune still looks for sale. Pretty good deal for $850.
http://www.jeepforum.com/forum/f126/4-1-klune-david-853990/

Just saying...