After a month or so of research and trying to figure out how to put this fuckin thing together i decided to put a thread together showing a detailed way of putting the Box 4 Rocks kit together. Believe it or not it's actually quite simple. Don't for those dumbasses who can't read I've got plenty of pictures (i bet TJP is bout SHITTING HIT PANTS RIGHT NOW!!! : Anyway, here goes:

Parts included in the kit:
http://i41.photobucket.com/albums/e287/akxj/DSCF1132.jpg
Backing plate and clocking ring bolts
http://i41.photobucket.com/albums/e287/akxj/DSCF1134.jpg
231 to D300 shaft (23 spline in my case)
http://i41.photobucket.com/albums/e287/akxj/DSCF1133.jpg
new 231 guide rod for shift fork
http://i41.photobucket.com/albums/e287/akxj/DSCF1130.jpg
D300 clocking ring
1"x4" (i believe the measurements are correct) piece of aluminum used for blocking off the portion of the case after cutting off unuseable end.

not included:
Dana 300
http://i41.photobucket.com/albums/e287/akxj/DSCF1133.jpg
NP 231 Front half

Tools needed:
Misc sockets and allen wrenches
RTV
loc-tite

Alright:
You only want to keep the pieces of the NP231 you see in this picture, nothing more nothing less--makes sure you have the pads....despite what the stealership has in their parts records they have differents pads for differents year shifter forks so not all 231's are the same (TRUST ME I KNOW)

http://i41.photobucket.com/albums/e287/akxj/DSCF1133.jpg
**DISREGARD SHAFT AND GUIDE ROD--they come w/ the kit

With only front half of 231 case left bolt 'b4r' backing plate on; draw line with marking tool:

http://i41.photobucket.com/albums/e287/akxj/231weld.jpg

Weld block into case ONLY!!! here's a picture of a case i found on pirate:

http://i41.photobucket.com/albums/e287/akxj/231cut.jpg

after block has been welded to 231 case to reassemble parts like the picture shown:
http://i41.photobucket.com/albums/e287/akxj/DSCF1133.jpg

Next attach D300 clocking ring to D300 t-case using loc-tite and RTV
http://i41.photobucket.com/albums/e287/akxj/DSCF1135.jpg
http://i41.photobucket.com/albums/e287/akxj/DSCF1136.jpg

Next I made a sight tube on my 'b4r' backing plate like this:
using two of these:
http://i41.photobucket.com/albums/e287/akxj/DSCF1137.jpg
and some tube i took the top screw and the bottom brass allen screw out and replaced like so:
http://i41.photobucket.com/albums/e287/akxj/DSCF1138.jpg

This is probably where you probably where you wanna put the 231 on the vehicle and then the D300 (at least that's what i'm gonna do). I would also maybe mock it up outside the vehicle a few times and mark the backing plate and the clocking ring to save some time since that D300 is pretty damn heavy.

Now attach the backing plate to the clocking of the D300 using the bolts provided in the kit like so using lots of RTV:

http://i41.photobucket.com/albums/e287/akxj/DSCF1139.jpg

Then attach D300 to 231 no forgetting shift fork/guide rod spring for the 231 case using the bolts provided it should look something like this; remember RTV is your friend cause leaks 2 weeks later really suck balls:

http://i41.photobucket.com/albums/e287/akxj/DSCF1140.jpg

or about a thousand different ways depending on how it's clocked.

Please feel free to add pictures and info for those who have already done this; this is not the all inclusive thread but i'm sure it will help a few out.

Sweet just what I needed!!

Thanks.

Nice build, just curious about how much time you spent?

spent putting it together, not really long at all....research awhile, i don't think the install will be to bad....the shifters are gonna be bad i think....

:beer:

I take it you found the correct pads?? :smokin:

Damn Eric the shit missle isnt going to go anywhere with all that gearing......... I like it tho!!!!!!!!!!!! Can not wait until its done........ Going to put all other Cherokees to shame around here thats for sure!!!!!!!!!!!!!!!!!


James

Nice.. cant wait to see it all mocked up:D .... I guess I need to get motivated and start putting together my shit now

I learned this the hard way yesterday:

the input shaft on a 04 TJ 231 (5 spd i'm sure) is longer than that of 99 XJ 231 input shaft. Glad i live really close to a machine shop....bear in mind not all 231's are the same!!!

Tech to the top BS to the bottom...

clean up

are you running a pass drop 60. does the box for rocks kit allow the 300 to be clocked drivers drop or do i have to drop the $ for a flip kit as well. i have seen the shifter flip for the 300 but am not sure how well it works i would like to run the same setup but need it drivers drop. any help is appriciated

KEEP US POSTED ON THE SHIT MISSILE, props on the build

i just flippin it on the cheap w/ the kit from duffy w/ the shifters that he made....i really haven't figured out how people put an extra seal in the shift rails...i figured i would throw a little RTV around them and call it good if they start leaking at all....we'll see....i'm run a ford hp60

Since you labeled it as for Dumb Arses, I'll ask a dumb arse (or inexperienced ) question: What are the "pads" you are talking about? I've never taken a T-case apart (yet). Got a pic of them by any chance? I am a better visual learner anyhoo! Thanks in advance, feel free to flame away.

i just flippin it on the cheap w/ the kit from duffy w/ the shifters that he made


good to hear, post up some pics of the shifters once you get everything in place, im in the process of putting the same setup together

Since you labeled it as for Dumb Arses, I'll ask a dumb arse (or inexperienced ) question: What are the "pads" you are talking about? I've never taken a T-case apart (yet). Got a pic of them by any chance? I am a better visual learner anyhoo! Thanks in advance, feel free to flame away.


see the translucent square pieces in the third picture from the top by the shift, those are the pads that i speak of...

see the translucent square pieces in the third picture from the top by the shift, those are the pads that i speak of...

Ah, ok. The little ones on the shift fork around the collar of the main shaft. Gotcha. Wouldn't have noticed that that they were separate or translucent without being pointed out from that picture. Thanks!

http://mindstormsolutions.homestead.com/files/DSCF1133.jpg

Do you have any shifter pics of the cases in the XJ?

I bought this kit used from a guy off of Pirate that attaches a 231 to a 300. But i cant decide if i want to run a chevy 60 or a ford 60.

updates?

I just drilled the tranny about a week ago, and i'm currently working on the tunnel cover for it, then onto the crossmember for the D300 when all that is done it should be good to go...

i'm currently working on the tunnel cover for it

Yeah, that makes two of us. :D

http://www.phatserver.net/~chris/XJbuild/062007/DSC01863.JPG

I decided to start over on mine, it wasn't worth fucking around with making little patch panels and shit.

Do you have any shifter pics of the cases in the XJ?

I bought this kit used from a guy off of Pirate that attaches a 231 to a 300. But i cant decide if i want to run a chevy 60 or a ford 60.

I run a Dodge 60 which is basically the same as a chevy. This is how it shifts.

http://www.phatserver.net/~chris/XJbuild/111906/cable1.JPG

You can also see why I decided to go to plan B, as shown at the top of this post.

I can see your XJ looking a lot like ASHMAN'S in the future!:eek:

I can see your XJ looking a lot like ASHMAN'S in the future!:eek:

Well, I'll be framing out a new tunnel around everything and having removable skins on it. It'll look a lot more finished once everything is painted etc.

I've still got much more body that Ashman has, I guess it'll just be a matter of time before it goes away though. I'd like to keep it together as long as possible though.

http://www.phatserver.net/~chris/XJbuild/062007/DSC01846.JPG

Doors still go on, A/C blows nice & cold, and the stereo's pretty damn good too. :)

i got duffys cheap flip shifters , and they come out pretty much where the stock tc shifter comes out , just needed to cut back about two inches as the shifters have lots of throw. Also need to bend them abit to clear my seat but seems to work well. You guys have any sealing problems I thought i used plenty of rtv but still got a slight leak around the clocking ring.

iYou guys have any sealing problems I thought i used plenty of rtv but still got a slight leak around the clocking ring.

Yeah, I have a small one at the same spot. I only applied RTV to one side of the clocking ring though (between the ring and the NP231 adapter plate). Next time I take it apart I'm going to put some stuff on both sides of the clocking ring.

I also recommend putting some sort of sight tube on it so you can keep an eye on the fluid level; you can sorta see mine in the pic above. I can get the part numbers for the fittings and stuff I used if needed.

yeah i only did the one side also. I am in no hurry to take my all out again though not yet anyways.

i just flippin it on the cheap w/ the kit from duffy w/ the shifters that he made....i really haven't figured out how people put an extra seal in the shift rails...i figured i would throw a little RTV around them and call it good if they start leaking at all....we'll see....i'm run a ford hp60


I put the second set of seals in the little metal piece that bolts to the front of the aluminum piece. Pretty much the two seals end up being back to back. Add some RTV and no leaks yet.

Not real sure I understand what I am looking at other than you combined a 231 and 300. What are the gains here? Is this like doing a dual case build? Can someone please educate me or send me somewhere that has the info?

Not real sure I understand what I am looking at other than you combined a 231 and 300. What are the gains here? Is this like doing a dual case build? Can someone please educate me or send me somewhere that has the info?


Pretty much a dual case build. You are using the 4wd LOW aspect of the 231 to feed the 300. If your 231 4wd LOW is 4:1 ratio and the 300 was 4:1 in 4wd low, now you have a 16:1 crawl ratio at the 300 outputs. Of course, these aren't the stock ratios for these tcases, I was just using the numbers. Also, since you do not need any other aspect of the 231 other than the 4wd LOW, you only use the front of the case and chop the side off it that the front driveshaft would come from, since that DS now comes from the flipped 300, which would hit the 231 if not cut off there.

Awesome pics and step-by-step... You make it look pretty easy. Definitely something to consider.

I just ordered my Box 4 Rocks kit about 30 minutes ago. I will post my progress.

Anyone have pics of their mounted box 4 rocks kit with dual 231's.

my 231/231 setup:

http://www.petrisimolin.com/ThePalsta/topic.asp?TOPIC_ID=26100

nice. that setup is pretty freaking long though. anyone have pics of it actually in their jeep?

Anyone have pics of their mounted box 4 rocks kit with dual 231's.

Benefits of the 231/231 over 231/300 built? I know the 231 would need a SYE and w/o a super short SYE the t-case would end up longer overall?

The only one I see is a standard drivers side drop vs using a flip kit with the 300. What am I missing?

Benefits of the 231/231 over 231/300 built? I know the 231 would need a SYE and w/o a super short SYE the t-case would end up longer overall?

The only one I see is a standard drivers side drop vs using a flip kit with the 300. What am I missing?

No Twin stick for dual 231's also.

ive got mine in probably 1500 miles or more on it {dd} still got work to do before its all done like mount my 5 foot front drive line and build a trac bar. besides that it went together pretty smooth.

my 231/231 setup:

http://www.petrisimolin.com/ThePalsta/topic.asp?TOPIC_ID=26100

I got all excited when I saw this, but then I checked the link and all my expectations came crashing down...:(

Besides the fact that I can only read English (and a tiny, tiny bit of Spanish), that really does look WAY too long. Guess I'ma go hunting for a D300.

How much oil do you put in the crawler case and do you have to make your own hole to fill it?

How much oil do you put in the crawler case and do you have to make your own hole to fill it?

The box4Rocks plate has brass hex head plugs for fill and drain, look at the picture on the first page The one in the middle is the fill.

Thanks. That is going to take a long ass time with a heavy weight oil.

Thanks. That is going to take a long ass time with a heavy weight oil.

Don’t fill it with Oil. When I was talking to Duffy(D.D. Machine) he suggested using ATF. The 231 runs ATF from the factory and ATF dissipated heat better then heavy weight oil anyway.

Don’t fill it with Oil. When I was talking to Duffy(D.D. Machine) he suggested using ATF. The 231 runs ATF from the factory and ATF dissipated heat better then heavy weight oil anyway.


Yup Normally gear oil in a 231 = :nuke: You might get away with it in the doubler since there is no pump, but ATF is the correct lube.

Nice writeup. I'll hopefully be doing a 231/242 setup sometime in the future. One thing I'm concerned about is clearance in the trans tunnel... not sure how different the MJ tunnel is from an XJs.

I'm actually doing a doubler in a comanche right now and this is the hole you will have to cut to run those cases clocked at the stock angle.
http://i214.photobucket.com/albums/cc231/whwheeler21/IMG_0302.jpg

Where did you get the adapter and kit from? MadRooster or Duffy? How much was it delivered. Looking to do the same on my MJ. Sould bw sick Got the Tera Low in the 231 so the stock D300 should be fine with a set of twins.

Got the kit from duffy. Way cheaper than madrooster and same quality if not better. Teralow with a 300 behind it will be sick and you probably won't have to cut that hole in the floor. I had to because im running dual 231s just cuz they are dirt cheap.

Well check this out. It says your in San Luis right? Ill be moving to Morro Bay next saterday. Will Be working @ Cole Chrysler. Neet shit. I found a twin cable shift for the 300 as well so I wont need to cut a big ass hole with that. WIll be sweet.

Dave

Ok, here's a question. What about clearance over the crossmember for the front driveshaft? With the front output moved back, I can't see this working... (assuming stock clocking angle 231/242 combo)

Ok, here's a question. What about clearance over the crossmember for the front driveshaft? With the front output moved back, I can't see this working... (assuming stock clocking angle 231/242 combo)

Somehow I doubt that he's going to be able to use a stock crossmember - adding 7" to the driveline. The tcases are going to need to be supported, or bad things will happen.

Yes, the rear case needs to be supported by a second crossmember and you have to run a 2 piece driveshaft with bearing on the forward crossmember. I am working on those two things right now and will have pics in a couple days, or check out
http://www.pirate4x4.com/forum/showthread.php?t=507763&highlight=stretch+111

Just as a little aside...

With a D300 as the second case I'm running it unsupported and you don't need a carrier bearing. I've yet to see a second support that I really like, and after a year of beating the shit out of it and breaking a ton of stuff, nothing has happened to the t-case arrangement...so at this point I'm not worried about it.

The 231/242 is a little lighter but also has the weight a lot further out, so YMMV.

Ya. I wouldn't run a second crossmember with a D300 or a two piece shaft, but with dual 231s or a 231/242 combo I think both are necessary just because the rear case is so far back there.. Sorry I forgot to mention the cases I was running in the previous reply.

Yea, I figured I would have to run a support, just wasn't sure about the front DS.

i'm running a second crossmember on the shit missile...i believe there's some pics on the thread...

With a D300 as the second case I'm running it unsupported and you don't need a carrier bearing. I've yet to see a second support that I really like, and after a year of beating the shit out of it and breaking a ton of stuff, nothing has happened to the t-case arrangement...so at this point I'm not worried about it.


Now you have be really thinking that I shouldn't even bother building a crossmember for the t-case.

I had been rolling around the idea of building some type of support for the 300 when I added in my box4rocks, but most of secondary t-case supports that I have seen look like they would actually put more stress on the 231/300 than just letting it all float behind the transmission mount. Assuming engine and tranny aren't solid mounted...

For anyone using a 2-piece shaft to clear the crossmember, Which vehicle did you get the carrier bearing and shafts out of?

Holly shit is there alot to it. Fuck it's almost worth buying one put together already.

Holly shit is there alot to it. Fuck it's almost worth buying one put together already.

Huh - except for welding on the blockoff plate, a monkey could assemble one in 15 minutes.

i dont have carrier bearing in front DS (231/231 + LP D44)

crappy pic:

http://static.petrisimolin.com/gallery/data/images/Jeeper-P3080005_640x480.JPG

^?????

I got a quick question for you, did you drill out the holes in the tranny mount to fit the clocked 231? To fit mine all together I have to rotate the 231 almost 180 degrees but the mount on mine is set to only go in one way, is off by abount 1/4" on 3 bolts. Before I go wild drilling wanted to see what you did for it.

Figured it out. Used my buddies old toyota parts if anyone wants to know. Thanks.

Then attach D300 to 231 no forgetting shift fork/guide rod spring for the 231




What spring are you refering to? I have all parts but dont have or see a spring. Thanks :)

Then attach D300 to 231 no forgetting shift fork/guide rod spring for the 231




What spring are you refering to? I have all parts but dont have or see a spring. Thanks :)

The only spring related to the 231's shift fork if for the detent ball.

Here's a write up for a 231/300 doubler and a home made flip kit for anyone interested.

http://www.rockhardxj.com/viewtopic.php?f=2&t=1686

that makes good sense thank you.:D

Ok I am a noob... are you running that on a drivers side drop axle?
I am told you have to flip the entire unit to run drivers side drop, I don't want to do that because I don't want to redrill the mounts on the tranny.

Is it possible to run a stock clocked 231 and flip just the 300?

From a PM I sent Desert CJ,
You flip the 231 crawl box AND the d300 together as one unit and then use clocking rings to dial in the position that you want. Yes, you will need a flip kit for the 300 or you'll have to rig up some cable shifters for it as well as fab a shifter for the 231 crawl box.

Where can I get this Box 4 Rocks kit? It sounds much cheaper than a Klune-V.:D But more work.:(

Where can I get this Box 4 Rocks kit? It sounds much cheaper than a Klune-V.:D But more work.:(

Last I heard, Duffy wasn't making the Box4Rocks kit anymore. I'm not sure if desertCJ is making the Mad Rooster kit either. I sent him a quick email, but I haven't received a reply yet. I'd love to buy a doubler kit for a 231/231 this summer if they're available.

Where can I get this Box 4 Rocks kit? It sounds much cheaper than a Klune-V.:D But more work.:(http://www.pirate4x4.com/forum/showthread.php?t=660037&highlight=box+rocks

http://www.pirate4x4.com/forum/showthread.php?t=660037&highlight=box+rocks

Thanks.:D

I`m still making them and have "LOTS" in stock, I was sold out for a few months well I made a big run of them but know I should have time to keep them in stock , it had got to the point were I was sold out before I could get a run done so I had to make a huge run to get to the point were I could have them in stock ready to ship,

Thanks
Duffy
D.D.Machine
shop # (360)779-2500
cell # (360)649-4465

( P.S. I normaly can`t get to the phone in the shop, so please leave your # and I well call you back when I shut down for the day)

I`m still making them and have "LOTS" in stock, I was sold out for a few months well I made a big run of them but know I should have time to keep them in stock , it had got to the point were I was sold out before I could get a run done so I had to make a huge run to get to the point were I could have them in stock ready to ship,

Thanks
Duffy
D.D.Machine
shop # (360)779-2500
cell # (360)649-4465

( P.S. I normaly can`t get to the phone in the shop, so please leave your # and I well call you back when I shut down for the day)

Thanks for the reply! If you're still going to be making them through the summer, I WILL be ordering one in July/August. I have three 231s here, and would looooove a doubler. :)

so how much is one of the kits?? and who all makes them? Duffy, Madrooster,... what is the Cheapest?

no help huh?
hmmm

i need to buy one of these off of somebody.

no help huh?
hmmm

i need to buy one of these off of somebody.


must be tuesday , read the fukin thread:shaking:

I`m still making them and have "LOTS" in stock, I was sold out for a few months well I made a big run of them but know I should have time to keep them in stock , it had got to the point were I was sold out before I could get a run done so I had to make a huge run to get to the point were I could have them in stock ready to ship,

Thanks
Duffy
D.D.Machine
shop # (360)779-2500
cell # (360)649-4465

( P.S. I normaly can`t get to the phone in the shop, so please leave your # and I well call you back when I shut down for the day)

:flipoff2:

ttt i am just bumping this cause i am building one right now
and i am a dumbass

just bumping this since I'm setting mine up when it arrives in a few days

I'll be installing mine this fall hopefully...I have been laid off 3 times in the past year so dropping money into my TJ is scary.

im collecting parts to build a 231/300

but do you need a 2 piece shaft up front to clear the cross member. seems like theres people going both ways in this thread, and id rather not have to go that route.

assuming you're talking about drive shatfs? I'm not seeing any 2 piece shafts that are being used for that reason. Most applications where a 2 piece shaft is used is because of various susp. setups, motors, trannys, etc. not just because they are running a doubler.

i didn't need a 2 piece driveshaft for my front...just a thought...

ok..im guessing since you can clock the 300 up it helps some. i just done see how moving the yoke back that far, combined with droop on the driver side doesn't cause big problems

People have been running dana 300s in YJs and TJs for years now with 1 piece drive shafts. Moving it back 6-8" with the doubler doesn't affect anything besides the lengths and the angles of the shafts.

I got a quick question for you, did you drill out the holes in the tranny mount to fit the clocked 231? To fit mine all together I have to rotate the 231 almost 180 degrees but the mount on mine is set to only go in one way, is off by abount 1/4" on 3 bolts. Before I go wild drilling wanted to see what you did for it.

anyone have an answer to this? Im having the same problem. whats the right way to do this? trying to run a flipped 300 behind my 231. I need to rotate the 231 180deg but the bolt pattern doesnt allow this.

Ya that is what I had to do. I just took a dye grinder and opened up the hole. I am back to having it in the stock position again since I went over to a passenger drop. And I did it two years ago so I completely forgot.

Ya that is what I had to do. I just took a dye grinder and opened up the hole. I am back to having it in the stock position again since I went over to a passenger drop. And I did it two years ago so I completely forgot.
thanks, did it take a lot to open the hole up?

thanks, did it take a lot to open the hole up?

I think it took about 1/4' or 3/8". I just took a carbide bit and a dye grinder to it. It was pretty easy. Just a pain when you think you have enough out of it then you lug the case into place and it still isn't enough.

what are you guys replacing the yolks with on the 300? does the 231 yolk fit the 300, the 300 has tiny bolt holes...thanks....

I'm using 231 CV front yokes on the outputs of my 300. CV drive shafts front and rear.

I made another clocking ring for the 231 so that I didn't have to slot the holes in the tranny. So now I have two clocking rings to get everything lined up the way I wanted it.

Thought I seen somewhere on here that sombody ground some of the 231 shift fork off to get rid of the detents for 4H and N Any body got info on this????

Are you referring to the 300?

Thought I seen somewhere on here that sombody ground some of the 231 shift fork off to get rid of the detents for 4H and N Any body got info on this????
yea I saw that too, but dont think it was here. a guy ground some of the notches out of the np231s shift detent "collar" to allow it to shift straight from "2 hi" to "4 low".

There's no way in hell I'd go through all this craziness to put a 231 crawl box
under my rig. I wouldn't even consider it, you notice.. People always have trouble with them. No thanks.

Get a 300 Stak Replace-a-case or a NV241 Rock Trac from a Rubi.
Done, call it a day.

Ultra Low gears are only good out west wheeling on solid rock,
so you can crawl the dry rocks.

If you buy 5.38s and run a 4:1 low range... That's
way more than low enough for any east Midwest or East Coast wheeling!!
You need wheel speed!!

There's no way in hell I'd go through all this craziness to put a 231 crawl box
under my rig. I wouldn't even consider it, you notice.. People always have trouble with them. No thanks.

Get a 300 Stak Replace-a-case or a NV241 Rock Trac from a Rubi.
Done, call it a day.

Ultra Low gears are only good out west wheeling on solid rock,
so you can crawl the dry rocks.

If you buy 5.38s and run a 4:1 low range... That's
way more than low enough for any east Midwest or East Coast wheeling!!
You need wheel speed!!

opinions are like assholes bro....this a tech forum for those that want to go this route...so can it!!!

There's no way in hell I'd go through all this craziness to put a 231 crawl box
under my rig. I wouldn't even consider it, you notice.. People always have trouble with them. No thanks.

Get a 300 Stak Replace-a-case or a NV241 Rock Trac from a Rubi.
Done, call it a day.

Ultra Low gears are only good out west wheeling on solid rock,
so you can crawl the dry rocks.

If you buy 5.38s and run a 4:1 low range... That's
way more than low enough for any east Midwest or East Coast wheeling!!
You need wheel speed!!
Sure I'd run a NV241 if I had an auto....

That may be the case wherever you are from but when I ran my teralow 231 and 5.13's with 38'' SX's it wasn't near low enough. (YJ 4.0L AX15)...My new setup with the B4R kit should be plenty.

There's no way in hell I'd go through all this craziness to put a 231 crawl box
under my rig. I wouldn't even consider it, you notice.. People always have trouble with them. No thanks.

Get a 300 Stak Replace-a-case or a NV241 Rock Trac from a Rubi.
Done, call it a day.

Ultra Low gears are only good out west wheeling on solid rock,
so you can crawl the dry rocks.

If you buy 5.38s and run a 4:1 low range... That's
way more than low enough for any east Midwest or East Coast wheeling!!
You need wheel speed!!

You're an idiot. I never had any problems with the doubler's i've set up.

You want wheelspeed? How much? With 1:1, 2.72:1, 4:1, and 10.88:1 options i could stay in my powerband for any type of wheeling (dunes, rocks, snow, desert).

11.2, You mean 10.88? also forgot the 1:1 which would be the best example for your argument. (wheel speed)

11.2, You mean 10.88? also forgot the 1:1 which would be the best example for your argument. (wheel speed)

Thanks for checking the math, i sucks at the multiplying. (I didn't use the 1:1 much with the 4.0L but i guess its still there)

Thanks for checking the math, i sucks at the multiplying. (I didn't use the 1:1 much with the 4.0L but i guess its still there)

Yep sure is. I drive on the road so I use it fairly often.

Does anyone know if he is still selling these "kits"? I would like to get my hands on one.

D.D. Machine check the vendors section under engines/transfer cases.

what happens to your speedometer, with the NP231/Dana300 crawl box? is the 231 compatable with the 300 or will I need to weld up the hole on the 300?

Thanks

what type of shifter do you guys use for the 231?
i have a twin stick cable shifter for the 300 case.

I found this setup. Looks pretty sweet.

http://www.pirate4x4.com/forum/showthread.php?t=917356&highlight=np231

anyone have an answer to this? Im having the same problem. whats the right way to do this? trying to run a flipped 300 behind my 231. I need to rotate the 231 180deg but the bolt pattern doesnt allow this.

thanks, did it take a lot to open the hole up?



Which 3 of the 6 transmission holes did you choose to open up ?

seems like it lines up on either the top and left 3 or it lines up on the bottom and right 3 (looking from the rear)

The holes on the right of the tailhousing (looking from the rear) are the ones I egged out.

Anyone feel like giving me a measurement for the thickness of the block off plate for the 231? Im making my own 231 doubler with the help of a couple machinist friends and one wanted to know what kind of stock everyone else's plates were made of.

for those wanting to put this in a dakota, the shifters D&D sell, while of great quality, dont work well for my application. They come up through the floor almost touching my right leg, real close. and because the case is flipped and the hinge point of the shifter handle (the fulcrum) is so low, the shifter throw is really long. This makes it difficult to shift without cutting a huge hole in the floor for the shifter throw.
I will be replacing the set-up with a cable shifter set-up.

If you're still leaking, try using a product called "the right stuff" instead of standard rtv. get the caulking tube, not the spray can. this stuff is no joke, it will seal anything, instant fluid ready, instant pressure ready, can withstand and fluid in your car (yes brake fluid to), and its the only sealer that will fully set up while submerged in petroleum products. I never wheel without it.

Just realized I sound like a salesman...

This may have already been covered earlier in the thread but how strong are these things? What kind of HP and TQ will they take.

This may have already been covered earlier in the thread but how strong are these things? What kind of HP and TQ will they take.

The same amont of HP and TQ that a np231 and D300 can take.....:flipoff2:

Seriously though I did a lot of research before deciding to build one. Some people might tell you different BUT from all the info I gathered, it seems they only fail if you land on your driveshafts hard (which is the same for a regular np231) OR if you dont have a secondary crossmember suport for the rear case/dana 300. In both cases the doubler case cracks. I havent seen to much worse. I did see a D300 case bite the dust once too.

I think it all depends on how you wheel and what tires/axles you are running in your rig. If you are building going with a one ton set up you might be better off with a one ton doubler or atlas....Just my opinion.

thanks for the info

The same amont of HP and TQ that a np231 and D300 can take.....:flipoff2:

Seriously though I did a lot of research before deciding to build one. Some people might tell you different BUT from all the info I gathered, it seems they only fail if you land on your driveshafts hard (which is the same for a regular np231) OR if you dont have a secondary crossmember suport for the rear case/dana 300. In both cases the doubler case cracks. I havent seen to much worse. I did see a D300 case bite the dust once too.

I think it all depends on how you wheel and what tires/axles you are running in your rig. If you are building going with a one ton set up you might be better off with a one ton doubler or atlas....Just my opinion.

u are kind of right about the amount of hp and torque the cases can take. in high/ high range or high/lowrange (second case) it is the same. but if you have a 100 hp put thru 2.72 low than 2.62 off the 300 the outputs are seeing much more torque than they would stock. the 231 can probably take much more hp and torque input with doubler setup since it no longer has a front output with a chain trying to deflect and flex the case.
i love this setup works awesome!
some advice tho
if using 1 lowrange use dana 300 or whichever case is rear case
dont use front lowrange and rear high, unless you like broken inputs and output shafts.
if you crawl something in low/low than decide u need a hard bump or healthy wheelspeed to finish obstacle drop front case into high.

This is not a 231/300 but it a 241/205 is about the same build
Only thing is I can't find a kit for the 241/205 (ford 31 spline) I have talked to a few people but no luck yet.

Heres some pics of where I'm at

http://i1091.photobucket.com/albums/i399/littlejoe29h/8065388b.jpg

http://i1091.photobucket.com/albums/i399/littlejoe29h/979e258a.jpg

Have you called Duffy? I know at one time he was offering other kits

anyone got pics of their crossmember supporting the 300? looking for ideas

Have you called Duffy? I know at one time he was offering other kits

Do u happen to have his number or a link? Thanks

Do u happen to have his number or a link? Thanks

Duffy - D and D Machine: 360-649-4465

Thanks I talked to him today and should have the kit coming out next week

are many people are getting away with stock outputs on the 300? i just dont want to put it all together only to break them and have to pull it apart

I havent broken my outputs, but I've been pretty easy on mine.

i will probably only do a rear output for now, im not going easy on mine

can i use 90 wt. oil instead of atf in the 231 since it no longer has a chain? any pros or cons to that thought? is my logic fuked?

can i use 90 wt. oil instead of atf in the 231 since it no longer has a chain? any pros or cons to that thought? is my logic fuked?

Yea, I use the same oil in both my d300 and np231.
My logic was that the 231 no longer has an oil pump, so no reason for ATF. Its just a normal gear box now.

anyone talk to duffy lately? i have been calling him for the last week and getting his voicemail and no return call? trying to order a 231/300 asap

ok found a used kit missing the guide rod. can i just cut down the stock one?

Yup Normally gear oil in a 231 = :nuke: You might get away with it in the doubler since there is no pump, but ATF is the correct lube.

That was discussed on page 2..

Okay, so I have a question. People are talking about mating a 231 to a 300 and using the planetary & sun gear out of a 241.

So, why can't you just use the front half of a 241??

A 241/300 doubler.

It looks like the case should bolt right up just the same...I mean you already had to source a 241, right? And they're meant for v8's so I would assume the case would be stronger...

http://www.high-impact.net/transmission_and_gear/Tcase_NP241.htm

What am I missing here..? :confused:

I think I answered a small part of my question..

but still don't see the point in using any part of your 231 if you're going to be using 241 internals.

do the 241's really bolt up just the same like High Impact describes?


Out of the box4rocks vendor thread, first page:

Lumpdog
I still have a few of the 241 drivers drop setups in stock. There the same as the 231 only the big plate is larger. and I have a few 32 spline shafts on the shelf to go with them.

All you have to do is bore the back side of the "rear" shifter rail for a seal and make a new shiter shaft out of 3/4" drill rod. I have been using W1 steel
it runs about $20 for a 3 foot chunk,

I well sell of the last few 241 kits I have on the shelf for $475 + $15 shipping


Thanks
Duffy
D.D.Machine
(360)649-4465

if its going on the back of a jeep trans you will need a 23 spline input out of a 231 anyways

Aren't the 241's out of dodge v8's also 23 spline like the link I posted to High Impact says..? :confused:


"You can typically bolt a Jeep unit to a Dodge transmission and vice versa..."


************************************************** ************************************


Okay, well let me get a little off topic and throw a monkey wrench in there...I'm working with a 5.9L ZJ with 46RE trans and NV249 viscous coupling transfer case.

..better watch out it's vicious! :homer:

The 249, like all grand cherokees has a 'medium length' input shaft (0.840" I believe) and length needs to be matched..

Can I just find an NP241, order a 241/300 kit, and swap out the input shaft from my 249 into the 241....?


.

Not tryin to be a smartass here...anybody?