np242 "late design"

I am looking to upgrade my np231 to an np242 and see from Tom Woods site that there is an "early" and "late" design, with the late design seeming to be a better choice. What do I need to look for to buy one of these, any specific years or models? Also will the speedo sensor work with my '91 HO and AW4? Will I also need a new shifter and/or bracket? Just trying to make sure I get this right the first time...

Thanks for any help.

The early style had the yoke going inside the tailshaft housing, the late style has the yoke riding outside the housing. It just rides on the spline and goes up against a rubber boot. The late styles are usually more prone to vibs after lifting because there is less yoke support. If you do a sye on early or late I don't think it would matter because they both end up with the new style tail housing. Research that more. Why go to a 242? I know they are full time. It lets you drive around like its an all wheel drive car. It adds an additional limited slip differential inside the case. It provides a 48/52 % power split between the front rear. To me its one more part to break when you start wheeling it. The 231 is a beautiful thing. If it has regular fluid changes, don't grind it when shifting, it would last a zillion miles. Its easy to repair and the syes may be cheaper. Not sure??? Nothing wrong with 242 and it may suit your driving application better, but I like the added simplicity of the 231. They almost put 231's in Cracker Jacks and cereal boxes there are so many around.

My beater is for SUV duty not crushing boulders. I want the full-time 4WD for construction yards, muddy fields, and ski trips up the mountains. Yeah I would like to get a 242HD just for extra safety but it doesn't seem that anybody makes an SYE for them, and I'm not going to spend thousand(s) on a high-end transfer case. So yeah I know what I want and I just need buying advice thanks

That thread does not answer my questions does it

Here..

86-91 np242, 21 spline input, "Early" tailshaft housing
92-95 np242, 23 spline input, "Early" tailshaft housing
96-01 np242, 23 spline input, "Late" tailshaft rubber boot

You can swap an older 21 spline input into a newer case if you need to..

i've done this swap in a 2000 XJ. trust me, the question of 'late vs. early' models is a non-issue. late model 242s are ONLY for '97+ XJs. you need an early model. you can adapt one to the other, but do you really want to get involved in a big retrofit. just get the right one in the first place and save yourself the headaches.

yes, a major reason is the speedo will not work. use the shifter linkage from the donor vehicle, and it will work fine. if you are doing the tom woods sye (which i did), do a rebuild of the 242 tc at thsame time (which i also did), since you already have it open.

whether or not to do the swap is completely dependent on your use of the vehicle. if you are trail-only, by all means stay with the 231. if your XJ is your dd, don't listen to the 242 naysayers. yes, the 231 will take more abuse on the trail, but the 242 is quite capable on the trails. for a dd, the full-time 4wd option is excellent for wet roads and when snow is patchy. it was well worth the cost and effort for me.

Thanks guys. I'll just look around for one from my year. I've got a good tranny shop nearby and will have him rebuild while he's installing the TW SYE stuff. Should be as good as it can get after that.

altierior said:

i've done this swap in a 2000 XJ. trust me, the question of 'late vs. early' models is a non-issue. late model 242s are ONLY for '96+ XJs. you need an early model. you can adapt one to the other, but do you really want to get involved in a big retrofit. just get the right one in the first place and save yourself the headaches.

yes, a major reason is the speedo will not work. use the shifter linkage from the donor vehicle, and it will work fine. if you are doing the tom woods sye (which i did), do a rebuild of the 242 tc at thsame time (which i also did), since you already have it open.

whether or not to do the swap is completely dependent on your use of the vehicle. if you are trail-only, by all means stay with the 231. if your XJ is your dd, don't listen to the 242 naysayers. yes, the 231 will take more abuse on the trail, but the 242 is quite capable on the trails. for a dd, the full-time 4wd option is excellent for wet roads and when snow is patchy. it was well worth the cost and effort for me.

Click to expand...

Fixed it for ya smarty pants

ZacSquatch said:

Fixed it for ya smarty pants

Click to expand...

oops! can you forgive my error?

i stand by the remainder of my post, though.


except for the typos.

and except for any other errors.