NP231 vs NP 242

PRYAPSM · May 7, 2012

Here is my situation,
I ordered the wrong SYE and drive-shaft from TomWoods driveshaft. I didn't think to look at the tag on the transfer case, being lazy I thought hay its not all wheel drive so I don't have the 242, duh..

The question is, should I swap the transfer case to a 231 and keep the parts they sent me or keep the 242 in there?

I found a used transfer case for around $200 and they want a $400 core charge for the 242 parts..

Is there major differences between the two transfer cases?

Also I eventually plan to race in Jeepspeed..

Thoughts?

Johnnie Walker · May 7, 2012

THe 231 is supposedly strong due to not having the internal differential for the full-time (all-wheel drive). Major difference is 231 is part-time 4wd only. And 242 has full-time option. As you can probably tell, the 231 has more aftermarket support. There is also no "real" HD SYE shaft for the 242. The TW 242 SYE is a standard 242 shaft that has been cut and tapped. Choice really is yours.

2stix · May 7, 2012

if you are going to run jeepspeed, wouldnt you want to use a 2wd anyhow?

PRYAPSM · May 8, 2012

2stix said:
if you are going to run jeepspeed, wouldnt you want to use a 2wd anyhow?

You have to able to start the race with 4 wheel drive. Trust me it would nice to shave 75lbs.. Also I would like to wheel on the side.

2stix · May 8, 2012

cool, i did not know that. i have seen jeeps that were advertised as jeepspeed cars and they were 2 wd.
that said, i would go with a 231 since you can easily install a thick chain that will help withstand the stress of jumping and such.

PRYAPSM · May 8, 2012

2stix said:
cool, i did not know that. i have seen jeeps that were advertised as jeepspeed cars and they were 2 wd.
that said, i would go with a 231 since you can easily install a thick chain that will help withstand the stress of jumping and such.

Yeah thanks I am going to swap out transfer case, instead of waiting 2 weeks for tomwoods to send me a new drive shaft and output shaft.

Like people have said there is a tons of support for the np231..

souske · May 8, 2012

231=much simpler
A good thing on a race vehicle, and a jeep.

PRYAPSM · May 8, 2012

souske said:
231=much simpler
A good thing on a race vehicle, and a jeep.

So I found a 231 from 98 and mine is 98. IS there going to be any problem installing it? Is the spline count different, are the gears different, will all the bolts match up? etc...

scottmcneal · May 8, 2012

everything will just bolt up.I had no problems doing a friends setup.He went fromo a 242 to a 231.Even the lights on the dash worked

souske · May 8, 2012

The only issue might be spline count. Hopefully someone can chime in as to which was what.

PRYAPSM · May 8, 2012

souske said:
The only issue might be spline count. Hopefully someone can chime in as to which was what.

Yeah that sounds like it going to be the only issue! I tried calling the dealer and they were no help. Where or how could I find out what mine is???

scottmcneal · May 8, 2012

Spline count was the same on his.

PRYAPSM · May 8, 2012

scottmcneal said:
Spline count was the same on his.

on the transfer case to the transmission?

scottmcneal · May 8, 2012

Yes, it was a plug and play.No problems.They went to the 23 spline count in 90 or 91.I have put a 96 231 into a 98 that had a 242 in it to start with.Bolts right in.

PRYAPSM · May 8, 2012

scottmcneal said:
Yes, it was a plug and play.No problems.They went to the 23 spline count in 90 or 91.I have put a 96 231 into a 98 that had a 242 in it to start with.Bolts right in.

Did you have any problems at all? Anything I need to look out for? For example the torx bolt on top of the transfer case.

Thanks

scottmcneal · May 8, 2012

I have never found a torx on top of a t-case.Only on the trans to block.You'll need to remove the trans mount to see a bolt in there.It is very easy to change out.Have a friend help you with it, found this makes it go by fast and easy.I just use a floor jack when i reinstall the t-case, have your friend jack it up for you and then you can just slide it on and rebolt. I think a 9/16 worked better than a 14mm wrench.Just look to make sure you got all the nuts off.

MAKE SURE YOU BLOCK THE JEEP SO IT DOESN'T ROLL

PRYAPSM · May 8, 2012

scottmcneal said:
I have never found a torx on top of a t-case.Only on the trans to block.You'll need to remove the trans mount to see a bolt in there.It is very easy to change out.Have a friend help you with it, found this makes it go by fast and easy.I just use a floor jack when i reinstall the t-case, have your friend jack it up for you and then you can just slide it on and rebolt. I think a 9/16 worked better than a 14mm wrench.Just look to make sure you got all the nuts off.

MAKE SURE YOU BLOCK THE JEEP SO IT DOESN'T ROLL

Yeah we had a torx bolt on top of trans case..

Thanks for your help

KingIce · May 9, 2012

Novak Adapters has a very detailled overview on the differences of the 231!

Looki here: http://www.novak-adapt.com/knowledge/np_nvg_input_gears.htm

Swapping from an XJ of the same Year with the same Transmission should be plug and play!

PRYAPSM · May 10, 2012

KingIce said:
Novak Adapters has a very detailled overview on the differences of the 231!

Looki here: http://www.novak-adapt.com/knowledge/np_nvg_input_gears.htm

Swapping from an XJ of the same Year with the same Transmission should be plug and play!

Thanks good info!

NP231 vs NP 242

PRYAPSM

NAXJA Forum User

Johnnie Walker

Piece of Fish!

2stix

NAXJA Forum User

PRYAPSM

NAXJA Forum User

2stix

NAXJA Forum User

PRYAPSM

NAXJA Forum User

souske

NAXJA Forum User

PRYAPSM

NAXJA Forum User

scottmcneal

NAXJA Forum User

souske

NAXJA Forum User

PRYAPSM

NAXJA Forum User

scottmcneal

NAXJA Forum User

PRYAPSM

NAXJA Forum User

scottmcneal

NAXJA Forum User

PRYAPSM

NAXJA Forum User

scottmcneal

NAXJA Forum User

PRYAPSM

NAXJA Forum User

KingIce

NAXJA Forum User

PRYAPSM

NAXJA Forum User

Similar threads