Here's the deal: I wanna go 4:1
91 YJ, 4.56, 35's, Stock 4.0

I could 4:1 my T-case for like $1000+...

I could get a D300 and get a 4:1 for $675...

I know the output is pass side, so there's either a flip kit or Chevy D44 in the works...
How much is a flip kit? Is it do-it yourself-able? (I have minimal cutting rescources)


Or...Go for the queen mutha Atlas II? They start at like $2300 right??? <IMG SRC="smilies/crybaby2.gif" border="0">

Basically, should I put money into the NP231, fool around with a D300, or save for years for an Atlas???

The Atlas II 3.8:1 is $1820 and the 4.3:1 is $1990 from Rusty's. I think that would be my first choice because it is stronger that the dana 300. The 300 would come in second and the 231 would be way behind th rest.

The flip kit for the Dana 300 is do-able your self. The flip kit is around $600, but it includes Advance twin-stick shifters and all the special tools and parts needed to do the install. All the parts will run you about $1400. Saved me about $800 on an Atlas, and it was extra strength I didn't need with a TJ on 33's.

depending on how much cash you want to throw out there.. with your 4.0 you dont need an atlas... atleast for its strength..
i would go with a d300.. and get yourself a front d44.. use it as an excuse to do that job.. you'll be happier in the long run..
so think about that.. where do you see yourself in a few years.. what do you want to do.. dont buy for now.. buy for later.. do it right the first time..

Does anyone have any pictures or technical data as to why the 231 is so much "worse"?

Or is it all heresay?

Thanks.

The 231 is aluminum, ist chain driven, the 4:1 kit is $$$, its long, it can't be twin stick, did I mention its chain driven.

We make the Dana 300 Flip Kit here at Down East Offroad in N.C. The kit includes:twin stick shifter(same shifter the AtlasII uses)
2 shift rails,1 shift fork,all new seals,input bearing,detent box,2 tap and drill bit kits, 5 brass plugs,vent tube,shift fork pads, detent balls and springs, loctite, RTV and Color instruction manual w/ a speedo gear calibration chart.
The kit can be installed with common hand tools. Socket set and a hack saw or sawsall,
needed to trim the input bearing retainer.
It will bolt up to an AX-15 or NV3550 with no adaptor! You will gain 8" of rear drive shaft length over a skock NP231, and 4" over a NP231 with a S.Y.E. and 1.8" over an Atlas II. The 4:1, heavy duty rear output and the rear disk brake will work and install as normal. The kit is $695. Also no "Special" oil to use, just 80W-90 gear oil, and the speedo adaptor in the YJ's and TJ's will fit directly in the 300! Thanks Robert
<IMG SRC="smilies/biggrin.gif" border="0">

An Atlas would be do it right do it once - the Jeep could grow pretty big around it. The downside is that you have to budget money/time/parts for new driveshafts, body tub mods, and crossmember mods. On the other hand, its worth it. I pulled my SYE/4:1 equipped 231 and sold it after I saw too many 231 breaks, mostly chain related (I do wheel with a breakage prone crowd though). The Atlas 4.3 that's in there now is just so much better overall.

ATLAS ATLAS ATLAS...There is NO substitute IMO <IMG SRC="smilies/smile.gif" border="0">

I agree with these guys. I don't see a point to putting $1000 into a 231 case. It's just not that strong of a case to dump that much cash into.
It's kinda like throwing low gears and a locker into a dana 35C.
GO ATLAS.

Thanks for the info (DEO especially).

I really don't have any plans to go much bigger than 35's and my 4:1 for a very long time, so the Atlas seems like some serious overkill to me. I know it is the proverbial "shit," but if I can get a cheap D300 and do the other stuff myself, it would be a huge gain over the NP231 (gear driven, 4:1, shorter).

The cool thing is that between a flip kit, a 4:1 and (maybe) a beefy output shaft, the majority of the case gets replaced, so I could find a drestroyed one for basically free...

Originally posted by Eddie Mcstiff:
<STRONG>The Atlas II 3.8:1 is $1820 and the 4.3:1 is $1990 from Rusty's. I think that would be my first choice because it is stronger that the dana 300. The 300 would come in second and the 231 would be way behind th rest.</STRONG>

ONLY $1990? Are you sure? What is the site?
Thanks

http://www.rustysoffroad.com/

Thanks. <IMG SRC="smilies/massey.gif" border="0">

300 tera low is about 675
300 flip kit is if I remember corectly 475
www.downeastoffroad.com (http://www.downeastoffroad.com)

and if you do it get a t case disk brake too. <IMG SRC="smilies/biggrin.gif" border="0"> Then let me know the total cost.

Originally posted by crawlinTJ:
<STRONG>Does anyone have any pictures or technical data as to why the 231 is so much "worse"?

Or is it all heresay?

Thanks.</STRONG>

Not hearsay. Mine cracked twice. Always leaks.
noisy from the chain I think it grew.
Big cost for a short shaft kit. 399.00

cant wait to get rid of mine. Thank God I never had a teralow put in this pos.

Originally posted by crawlinTJ:
<STRONG>Does anyone have any pictures or technical data as to why the 231 is so much "worse"?</STRONG>

Personally, I've never seen or heard of one breaking.

I dont think it's so much a matter of being worse. I think it's about getting more for your money. For instance: If someone owned a YJ, they could spend the same type of money on fully upgrading the NP231 as they would for a D44 swap, with a Dana300, 4:1 gears and twinstick.

Junkyard Wagoneer front Dana 44 = $250
Dana300 = $250
D300 4:1 = $650
Twinstick = $100

Total $950


NP231 4.1 = $950
NP231 2wd lo = $180
Fixed Yoke = =$300

Total $1430

Granted both will need new driveshaft and there might be some extra money for regearing and refurbishing the dana44.

dude, how is rusty's so cheap? he quotes prices lower than the manufacturers themselves...

i didn't see his shipping rates, does he make it up there?

maybe just really low overhead...

Is a new front driveshaft needed for the D300 flip?

Originally posted by wrangler40:
<STRONG>dude, how is rusty's so cheap? he quotes prices lower than the manufacturers themselves...

i didn't see his shipping rates, does he make it up there?

maybe just really low overhead...</STRONG>

My guess would be VOLUME BUSINESS <IMG SRC="smilies/wink.gif" border="0">

no you can just get the front one shortened.

Call me a stupid newbie, but what's the T-case mounted disc brake for?
Is it a parking brake?
What's the gained advantage?
Does someone make one, or is it a homegrown torch and weld job?

Yep parking break.

since mine dont work anymore. And I like having one. Seams I am always in some wierd spot trying to help someone else out.

ie: reinflating a blown bead with my AIR.
Ie: Spotting someone.
Ie taking pics
Ie you get the hint?

So i like to have a parking brake. And a t case break is perfect.
One of the BB members Sorry I forgot your name. Makes one for a Dana 300 and I emailed him and he said it should work on a inverted dana 300 also. I am just trying to gather some more cash and here i go.

Hey Belly-

Does that guy make them for an Atlas II?

Thanks

Add up prices on the D300 flip idea.
D300 $200?
Flip Kit $650-700
4.1 gears $700
Rear drive shaft mods $100-250
You might as well save a couple extra beer cans a buy an Atlas <IMG SRC="smilies/idea.gif" border="0">

Any body heard of the strength of the atlas putting extra strain on the transmission? In theory it makes a little sence but I doubt the 4.0 can break the AX-15. I'm more worried about everything past the gear reduction.