What do you guys think the heavieast/biggest tire a NP231j can take with out breaking?

What can a 231 handle with a JB Conversions 1 ton shaft in it?


Im thinking 36's with the JB kit, would be the most you could pull off.. even then, you're pushing it.

Well...... I'm running 37" SSR's with just the Currie shaft in mine!

I ran a Klune-V in front of a Tera Low'd 231 with 38x12.5x15 TSL/SX's and had nary a problem with the 231. D44 axles on the other hand... :flipoff2: :beer:

shit, they sound pretty bulletproof then? unless you have major HP ..

glad to hear this

Originally posted by SOCALXJ
shit, they sound pretty bulletproof then? unless you have major HP ..

glad to hear this

Dunno about bulletproof. They ARE chain driven. I've heard of the chains breaking, cases splitting, and gears loosing teeth. It's all according to the way it's driven/wheeled.

It's a hell of a lot better than a 249!!! HAHA, here's what happens when you wheel one to destruction!
http://community.webshots.com/storage/1/v1/6/16/61/30561661dALhRwsUiP_ph
and here's my pirate solute...
http://community.webshots.com/storage/1/v1/6/16/54/30561654hZdJbhcYKe_ph

The 231 is so much better than what I had I love it! I run it with a v-8 35's locked and have had no problems at all with it.
-Nate

Originally posted by CannonBall

and here's my pirate solute...


complete with pirate spelling :flipoff2:

Thanks cock! :flipoff2: I SALUTE you in your quest to point out every spelling error on the earth.
-Nate

With the stock engine it should be pretty reliable up to around a 35 inch tire. Like somebody else said, it all depends on how you wheel it. I've run my 231 with 35s and a 258 for over a year now and no problems, but I'm sure there are people out there who will tell you theirs went :nuke: with 33s and a 4-popper...

Jake

My friend wheels his with 37" MT/R's and a 5.9L magnum motor putting out about 280 hp.

It's lasted through 3 trips so far, he's really just trying to see how much it can take before:nuke:

Then he puts more beef

If you would like to strengthen the chain assembly in the 231 there are a couple of options available to you.

JB Conversions offers a wide chain kit (chain and sprockets) for about $250 - 300 dollars,

Else,
You can get the Wide Chain and Sprockets out of the 91-92 Dodge Dakota Pickup WITH V8. These are a direct swap in.

TRW makes these parts, but most auto store will not be able to get them for you. (Maybe NAPA could.)

I would check with a Transmission Shop if you want to go this route.

Originally posted by Daless2
If you would like to strengthen the chain assembly in the 231 there are a couple of options available to you.

JB Conversions offers a wide chain kit (chain and sprockets) for about $250 - 300 dollars,

Else,
You can get the Wide Chain and Sprockets out of the 91-92 Dodge Dakota Pickup WITH V8. These are a direct swap in.

TRW makes these parts, but most auto store will not be able to get them for you. (Maybe NAPA could.)

I would check with a Transmission Shop if you want to go this route.

Polishing turds again Frank?

(--just kiddin' man :flipoff2: )

i wheeled the heck out of the 231 that used to be in my jeep. i did have the aa hd sye in it though. i ran 35x16 boggers and a d44/9 inch. broke about 5 d44 axles, 1 front d shaft, 4 rear d shafts and an unknown amount of u jionts.

Hey Jake, how are you today?

Yea well I guess you could say that, but there is another benifit!

Helps keep the forearms in shape!

Frank

O.K. question then. What is the major differences between the NP231j vs. the NP229 found in XJ selec-trac and FSJ? My NP229 has a fixed rear output, wheeled the piss out of it, and no problems yet. Thanx. :confused: :rasta:

Originally posted by mtndewmaniac
O.K. question then. What is the major differences between the NP231j vs. the NP229 found in XJ selec-trac and FSJ? My NP229 has a fixed rear output, wheeled the piss out of it, and no problems yet. Thanx. :confused: :rasta:

Selectrac (NP229) has a lockable, viscous-coupled center diff to provide AWD in 4 Hi and Part time 4WD in 4-LO. NP231 has no center diff nor a locker for it (since it doesn't have one and all :flipoff2: ).

Sounds too complex iff you ask me. More stuff = more stuff to break.

Why don't you get a NP241 out of a '90s fullsize Dodge or Chevy truck and do the simple mods required to put that in there? All you need is a JB SYE kit and possibly an input gear and/or front output depending on the year/configuration and whether it's a Dodge or Chevy donor.

You get a wider chain, bigger mainshaft, bigger front output shaft, stronger case, bigger planetary (handles more than double the torque that a 231 will handle) hell, bigger everything--and you can pick these up at the local yard for $300.

That's the route I'm going. Great solution for an SBC swap. Less convenient if you're not swapping engines at the same time though...

Here's some miscellaneous stuff I found on www.wagoneers.com about the NP229:

Selec-Trac Provides:
- Either 2- or full-time 4-wheel drive in HI range;
- An N (Neutral) position to disengage the axles from the powertrain
- Part time four-wheel drive in LO range.

Because selec-trac control functions are interrelated, mode
switch and range lever must be used in specific combinations
to operate the transfer case.

With range lever in the HI range, select either 2-wheel drive
(2WD) or full time 4-wheel drive (4WD) by moving the mode switch.
Mode selection can be made *WHILE THE VEHICLE IS MOVING
AT ANY LEGAL SPEED.*

NOTE: If mode switch is moved from one position to another
while the vehicle is not moving, it may be necessary to move
the vehicle forward or backwards slightly for the transfer case
to fully engage 4WD, expecially in cold weather.

If mode switch is in 4WD and the transfer case has completed
the shift, Selec-Trac offers a choice of HI, N, or LO rnages
by moving range lever. Range shifts must be made *ONLY AT
LOW SPEED 2-3 MPH, 3-5 KM/H)*.

CAUTION: Never attempt to engage LO range when vehicle
is in 2WD or when vehicle is moving faster than 2-3 mph (3-5
kmh). Transfer case damage may result.

*WARNING: NEVER PARK YOUR VEHICLE WITH RANGE LEVER IN THE
N (NEUTRAL) POSITION. THE VEHICLE COULD ROLL UNEXPECTEDLY
EVEN IF AN AUTOMATIC TRANSMISSION IS PLACED IN PARK OR A
MANUAL TRANSMISSION IS IN GEAR.*

Mode Selection (2WD/4WD)
Mode switch allows you to select 2WD or 4WD whenever you
wish, as long as range lever is in the HI range position.

NOTE: Complete transfer case engagment into HI must be
made before you can or should attempt to engage 2WD.

Range Shifts (HI-N-LO)
Range lever allows you to shift to HI, N, or LO range when
the transfer case is fully engaged in 4WD, the vehicle is
moving slowly (2-3 mph) and the *TRANSMISSION* is shifted
to neutral.

CAUTION: Do not try to move range lever from HI to LO when
mode switch is in the 2WD position. The range lever shift linkage
could be damaged.

- HI position
2WD or 4WD--In either position, the vehicle may be operated
on all road surfaces. In 4WD, Select Trac offers better traction
when roads are wet, snow covered or icy. Use Selec-Trac
4WD year-round (full time) if you wish.

- N Position (Neutral
In this position the axles are disengaged from the powertrain.
The vehicle may be towed without removing the propeller shafts.
Place an automatic transmission in Park or a manual transmission
in gear afdter the N position is engaged

- Lo Position
This position provides 4WD for occasional use when *OFF-ROAD*
driving conditions require low speed pulling power.

*WARNING: DO NOT DRIVE THE VEHICLE UNLESS THE TRANSFER CASE
IS FULLY ENGAGED. FAILURE TO COMPLETELY ENGAGE A POSITION
CAN CAUSE TRANSFER CASE DAMAGE OR LOSS OF POWER AND VEHICLE
CONTROL. bE SURE YOU KNOW THE SHIFT PATTERN OF YOUR VEHICLE.*

WARNING: DO NOT INSTALL SELECTIVE DRIVE HUBS ON SELEC-TRAC
VEHICLES. IF THESE HUBS ARE LEFT UNLOCKED WHEN THE VEHICLE
IS PARKED, THE VEHICLE COULD ROLL UNEXPECTEDLY--EVEN IF AN
AUTOMATIC TRANSISSION IS IN PARK OR A MANUAL TRANSMISSION
IS IN GEAR.*

just a side note...if im not mistaken, the XJ selectrac is the NP242 case. never heard of the 229.
what year are we talkin about?
~John

Originally posted by JohnBuuu
just a side note...if im not mistaken, the XJ selectrac is the NP242 case. never heard of the 229.
what year are we talkin about?
~John

You're probably right. The 229 came as the selectrac in a wagoneer and the 242 was probably the selectrac in the XJs... I think they both operate the same way (open LSD center diff in 4-HI locked center diff in 4-LO).

I think the 249 was full time AWD (open center LSD 4 hi always engaged) that was marketed as the quadratrac in ZJs (and maybe WJs?)

I don't fawkin' know. Somebody can feel free to correct me if I'm wrong... :flipoff2:

Jake

I know a 231 main shaft can be snapped with 38.5" tires and a 4.0 liter 6... I keep hearing people say that chain driven t-cases are weak, but I have still never seen a chain in one break.

Well I haven't had problems w/my np231 w/A.A. SYE. I have a Built Chevy 350 and Th350 in front of it. 400hp/450ft.lbs and 36's:flipoff2:

Originally posted by Duche79
Well I haven't had problems w/my np231 w/A.A. SYE. I have a Built Chevy 350 and Th350 in front of it. 400hp/450ft.lbs and 36's:flipoff2:

Automatic trannies are much easier on a transfer case than a manual. The combination of the tall gears (especially in the case of a TH350) and having a torque converter to soak up any sudden differentials between engine speed and wheel speed takes a lot of heat off your case.

I had serious doubts about my 231 lasting long behind my 350HP/400ft-lbs Ramjet 350 with an NV4500... so I figured I'd switch it out BEFORE it busted so I could get some cash out of it.

Jake

Maybe Frank could do a....Who has broken a 231 w/a wide chain in their own Jeep post .:laughing: Just kidding frank.

Hey Mr. RB, How you doing today.

That might not be a bad question!

My T/case (Wide Chain and TeraLow, HD SYE, 2Low ) will be coming down next week and put behind a NV4500 which is behind an LT1, which is all in front of a D-60 way in the back and a D-60 way up front (Don't remember the gears) in a friends Jeep.

He is a bit tentative. Thinks it might break!

I told him, it won't break.

Heck I haven't even been able to break a Super 35.

What makes him think this will break! :)

If anyone has an interest, I just noticed JB Conversions has BRAND NEW
NP231HD WITH The Heavy Duty Wide Chain and Synchro Ring, and the Short Shaft Kit already installed for $750.

When you conceder what you might be able to get for your old T/Case this might be a decent solution.

They also have the Wide Chain Kit reduced to $200.

Here's the link

http://www.jbconversions.com/pages/prod.html

I've got a brand new NV4500 and Atlas 3.8 sitting on my shop floor. Probably to go in next week as well.

Frank

I already have the AA SYE. If I replace the gears with Tera 4:1 gears, this also replaces the chain. How does the chain width compare to other stock applications like Dodge, etc?

Ive got a 231 with a high angle sye and driveshaft, stock 2.72 gears, and all that good stuff.. Ive beat the piss out of it pretty hard, and its holding up fine. course its behind an auto. With that said. I just aquired a daily driver, so its time to start looking for big parts, like a 60 front, D300, 14 rear... hehehe
Scott

Originally posted by 1990JeepXJ
I already have the AA SYE. If I replace the gears with Tera 4:1 gears, this also replaces the chain. How does the chain width compare to other stock applications like Dodge, etc?


who told you you get a new chain.... when i did my t case (many moons ago) i reused my original chain, tera doesnt send one with there 4 to 1

Ketchup, what did u buy for a daily driver?

Originally posted by 1990JeepXJ
I already have the AA SYE. If I replace the gears with Tera 4:1 gears, this also replaces the chain. How does the chain width compare to other stock applications like Dodge, etc?


Hi 1990JeepXJ,

Perhaps I am misreading your post. If I am, please ignore this.

The Tere4Low does not come with a new chain, but rather a new front half of the case which contains the new planetary gears for 4 to 1 reduction.

You retain the same chain, and sprockets that are in there now.

To answer your question on the chain size. The Dodge (or JB Conversion) Wide Chain is about 50% wider then the stock chain (and sprockets.)

Also, be aware of this.

If you go with the wide chain AND the Tera4Low unit AND the Tera 2Low sift selector, DO NOT use the drive sprocket with the Heavy Duty Synchro Ring !

It will not work.

You must use the standard Synchro ring, which is built into the drive sprocket.

Let me see if I can clarify that some.

The Wide Chain is more then just the chain, There is a wide drive sprocket and a wide front output shaft as well. (The chain goes around these two sprockets)

The wide drive sprocket comes in two flavors, with the heavy duty synchro ring OR with the standard synchro ring.

If you want to do all these things to modify your np231 T/case,

Tera4low,
Wide Chain Conversion,
and Tera 2Low,

You must get the wide chain WITHOUT the heavy duty synchro ring, else it will not fit. (It will bolt up, but it will not shift.)

Don't know if you were giving any thought to doing all this or not, but wanted to make you aware of this.

Hope this helps you out and I haven't added a layer of confusion here.

Frank

Thanks Frank. I thought the Tera front half would replace all or most of the internals with it. Had I known, I might have picked up the JB HD kit then just slapped the Tera stuff into it.

Originally posted by JohnBuuu
just a side note...if im not mistaken, the XJ selectrac is the NP242 case. never heard of the 229.
what year are we talkin about?
~John


The NP229 came in the XJ definitely in the years of 84-86, they may have ran longer than that, I'm not sure. The year range they're used in the FSJ, I don't know, but have seen a couple in them.
Didn't expect a book about this though :D But I apreciate your input. I knew what the NP229 was, but had no clue about the other. What I was really after was if they both could fit the same to the back of the (same) tranny. and as I had found out on a later thread, anything after '80 will.
for your time let me buy you one. :beer:

I have blown the 231 in half 5 times but not the fault of the case. Before the slip yolk eliminator kit was avail, the damn thing would bind and crack the bolts holding the rear ujoint. The next time I'd get on it, the drive shaft would come free and wrap into the muffler and from 3K RPM to 0 in .005 seconds. There I'd go....atf everywhere. wife (exwife now) towing my jeep behind her Bronce honking to all my neighbors to show the Jeep being towed again- Ate a lot of crow...
The plus side is you can buy a new shell from the dealer cheap stuff all the old parts in it and you on your way in under 5 hours, or spend the $ and get a 4:1 w/ a short shatf kit. I have 70K on it with out a single failure since. The 231 is under rated.

I know somebody who broke theirs with 33's and a 4 popper. The guys not to smart though. He forgot to take it out of four wheel drive on dry pavement.

OK 2 things,

When I did my V-8 swap I used an S-10 transfer case because it bolted right up to the back of the 700R4. As an added benefit, when I was putting the Currie kit (not the strongest, I know) from the Jeep transfer case to the S-10 transfer case I noticed that the S-10 transfer case had a wider chain, so I used the wider chain and sprockets.

I get pretty leery about bouncing up a hill while on the gas now, and I'm thinking of upgrading. I've broken the CV flange on my driveshaft so far, not the output shaft (thank god, not as easy of a fix).

How much longer is a np241 out of a Chevy truck. If I could fit one of these in with not too much change in driveshaft length that may be good.

Originally posted by BlueJeep

How much longer is a np241 out of a Chevy truck. If I could fit one of these in with not too much change in driveshaft length that may be good.

I've got both sitting on my workbench at home right next to one another. (Coincidentally enough, the 231 has a Currie SYE in it too :) )

It's hard to compare the lengths apples-to-apples yet because the SYE for the 241 hasn't showed up in the mail yet, but eyeballing it, I'd say the difference will probably be only one or two inches when it's all said and done. Probably even less, seeing how the Currie kit has the flange there will be just a straight yoke on the 241 when I get it converted which cuts off an inch or so compared to a flange...

Other than length, the 241 is larger in pretty much every measurable way though... makes the 231 look like a toy sitting next to it... :D

HTH,
Jake