Topic: NV231-D question

[dexetr30]

What's the difference between the NV231-D and the 231 that's in my TJ? Is the D version a direct replacement?

[Jeffy]

D is a dodge unit.Your Jeep had a NP/NVGG231-J.  GM's have a NP/NVG231-C.  There is another unit that is called the HD but I thin it's just like the D.  The J was the first. with a 3 gear planetary set and a 1" chain.  D's  are usually a 6 gear planetary and a 1.25" chain and sprocket set since they use them in the Dodge 1500 and the Dakota.  The C is the odd one.  Instead of a 6 bolt pattern on the front is had a 5 bolt pattern but will bolt to a 700R4 or the 4L60E.

Input shafts are all different as well.  GM's use a 27 spline.  I think Dodge and Jeep are teh only ones who use 21 and 23 spline but there are others.

All parts are interchangeable so if you wanted a HD then you can mix the 6 gear planetary and the 1.25" chain and sprocket set in a J to beaf it up.

[dexetr30]

D is a dodge unit.Your Jeep had a NP/NVGG231-J.  GM's have a NP/NVG231-C.  There is another unit that is called the HD but I thin it's just like the D.  The J was the first. with a 3 gear planetary set and a 1" chain.  D's  are usually a 6 gear planetary and a 1.25" chain and sprocket set since they use them in the Dodge 1500 and the Dakota.  The C is the odd one.  Instead of a 6 bolt pattern on the front is had a 5 bolt pattern but will bolt to a 700R4 or the 4L60E.

Input shafts are all different as well.  GM's use a 27 spline.  I think Dodge and Jeep are teh only ones who use 21 and 23 spline but there are others.

All parts are interchangeable so if you wanted a HD then you can mix the 6 gear planetary and the 1.25" chain and sprocket set in a J to beaf it up.

Going to the scrap yard this weekend. And particular Dodge models I should look at for the "D" version? I've been looking into a 241 but I've heard they are a different length. 

[Jeffy]

Going to the scrap yard this weekend. And particular Dodge models I should look at for the "D" version? I've been looking into a 241 but I've heard they are a different length. 

I "think" they're all the same.  Usually with a 316 V8.  Like I mentioned in that other junkyard thread, I'd probably look for a Dodge Ram 1500 or maybe a late model Dakota or Durango since those also have the 318.

The 241's length will depend on where it's from, Chevy or Dodge.  They are all the same length except for the tailcone.  Some are longer as even with a short tailcone, it will be LONG compared to the 231.  They are sort of a drop-in as they share the same 6 bolt pattern but you'll need to figure out a way to mount it.  The 241 is about 25% larger then the 231.  I'm not sure if anyone makes a SYE for it anymore.  Then you'll need to find a 21 spline input shaft for it.

Oh and all of the transfer cases will be marked on the ID tag..  So, 231J, 231D, 231HD, 231C, etc...

[dexetr30]

Cool. Thanks Jeffy.

I found some real good info on the different versions of the 231 and 241 in the link below. Seems as though the GM version of the 241 is rotated 90 degrees. Having all this info in front of me makes me want to pull entire drive train from something with a 318 and do an engine swap. 

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

If you look at the menu to the left on that page there are several links to many other transfer cases.

[Jeffy]

I haven't been to a junkyard in years!  Actually, it's probably been close to 10!  Bought all of my stuff off ebay and didn't get my hands dirty! 

I too wold consider a 318 swap from a Dodge.  I mean, if you're going to go through with a swap, you might as well, go with a V8.     Then again, a 360 Dodge 2500 isn't that far off either!   

[dexetr30]

I'd keep it simple. 318 w. a 727 and the 231D or the 241. The 318 would be a carbed 2 barrel (would still make way more torque than the 2.5) with the only accessories being the alternator and power steering pump. As little wiring as possible under the hood to keep it all real clean looking. This may be in my future.

[Jeffy]

I'd keep it simple. 318 w. a 727 and the 231D or the 241. The 318 would be a carbed 2 barrel (would still make way more torque than the 2.5) with the only accessories being the alternator and power steering pump. As little wiring as possible under the hood to keep it all real clean looking. This may be in my future.

Yuck, stick with the EFI, aka; 5.2L found with said transfer case.

[Bounty Hunter]

What is wrong with your 231 that you're looking to change it?

The 241 doesn't have much aftermarket support, not when compared to the 231.  The 231 can be built to handle more torque when you use the 6gear planetary and wider chain/sprocket set.

The 231j can be found with both the 3 and 4 gear planetaries, the latter being behind some 4.0L's.  A 6-gear can also be found in the 231c and 233c if they were behind a 4.3L or larger engine.

Most input shafts are interchangeable in the NP line of transfer cases, meaning you can use your current input shaft in another 231/241/242/247/249etc.  The main difference is early or late gear cut where it meshes with the planetaries.

[dexetr30]

Not looking to change it necessarily. Just trying to learn something about interchangeability and whatnot. Only way I might change it is if I did a complete engine/drivetrain swap. It's always good to know what fits/came with what. 

[Jeffy]

people actually did swap NVG241's into Jeeps for a little while.  That was around the same time HD SYE kits started appearing.  There was one company that made a SYE for the 241 but I forget who.  But like ^^ there isn't much available for it aftermarket.  That is unless you're looking at a NVG241OR.

[Bounty Hunter]

Most of the 241 and 242 SYE's I've seen have been of the hack and tap flavor.

I recently rebuilt my 231, removing the hack and tap for a super short SYE.  While I was in there, I threw in a 2lo, wide chain kit, and 6gear planetary.  The 4banger may not need the extra beef, but the piece of mind is nice.  2lo is sweet.

[chardrc]

is there a good place where one could research the interchangeability of 231 parts.... i tried a Google search but failed ...

[Bounty Hunter]

Not that I know of.  I do use www.novak-adapt.com and go to the 'knowledge' section for info on input shafts, etc.

I've got quite a few 231 parts, and parts from some other models, if you need anything.  I rebuild quite a few transfer cases for other jeepers, as well as build 231's to swap in place of 242's, 247's, 249's.

[dexetr30]

Most of the 241 and 242 SYE's I've seen have been of the hack and tap flavor.

I recently rebuilt my 231, removing the hack and tap for a super short SYE.  While I was in there, I threw in a 2lo, wide chain kit, and 6gear planetary.  The 4banger may not need the extra beef, but the piece of mind is nice.  2lo is sweet.

2lo...  I can't tell you how many times I have thought about that. I could have used a granny gear many times in 2wd. Where did you pick that up at?