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4x4Dad 05-03-2013 08:38 PM

What's involved in NP229 --> NP242 swap?
My 229 transfer case just imploded, right after I passed smog (the Jeep gods know I got a bit of tax money back this year). As I drove home in 2wd, it sounded like my kids eating hard candy near a PA system. Quite ugly.

I've got a line on a local NP242 with SYE from a Grand Cherokee. I've confirmed its a 23 spline, so I think it should bolt up to my TF727 okay.

But I'm not sure what I need to do beyond that.

I've read nearly every forum thread on NP242s, but I'm feeling in the dark still, so i felt I needed to post a thread. I know the rear drive shaft will need an adapter, at minimum, to bolt to the SYE, but will I have to buy an all new shaft? Is there an adapter that will allow my stock rear shaft to bolt up? Is there an XJ or ZJ shaft that I could use instead? (I'm assuming not because of the slip yoke feature, but I'd love to be corrected.)

What will I have to do differently to the front shaft?

A reman 229 is out of my budget range (upwards of $800 with tax), whereas the 242 with SYE is local and only $250.

Any insight/advice/experience you can provide would be great.

addicted 05-03-2013 09:17 PM

The 242 will probably have a different clocking to it so it will most likely hang lower.

Depends on the style SYE as to what type of shaft end you need to bolt it up.

Your shaft might be fine. The 242 is smaller than the 229 and shorter if I remember correctly so at most you'd need to have a new shaft made up or find a longer one and have it cut down. The front shaft should be fine unless it's out of a newer GC with the double CV front shaft. Then you will need to find an older style front output yoke.

You will need to do some shifter linkage mods to get it to shift with your current flag shifter.

You might be better off just finding a used 229 or 228 to swap in. They are cheap. I've never gotten more than $50 for the used ones i've sold. And they were all good.

babywag 05-03-2013 09:51 PM

AFAIK the NV242 Jeep front output yoke is the same as the NP229 so front should be fine.

If it has a slip yoke eliminator already you would bolt up the rear driveshaft the same way only issue would be length.

I have a longer rear shaft from a QT rig so if you do it and need a longer one...hit me up I'm fairly close probably ~70 miles.

4x4Dad 05-03-2013 10:29 PM

Thanks, guys. I'm going to pull the trigger I think and get the 242. I'm under a little time crunch, and 229s are nowhere to be seen around here. Besides, the 242 is a bit more popular and easy to manage repairs/upgrades/etc. And no VC to worry about.

I'll have to figure out the speedo cable adaptation, as well, but I don't worry how fast I'm going. I'm usually more concerned with how slow.

Tony, I will definitely keep that offer in mind as I do the R&R. I appreciate it.

4x4Dad 05-04-2013 06:03 PM

Bought it. Now I've got to install it. :D

As a nerdist academic, I'm going to think it through, buy what I need, take some pics, and perhaps post an overly verbose write up.

Carnuck 05-04-2013 06:25 PM

Did you see the post for a NP129 for $75?

pcoplin 05-04-2013 06:45 PM

The input shaft of the NP242 is shorter than the NP229. Make sure there is enough shaft engagement on the seal. If not, there are seals you can get that have a "snout" on them that will reach 3/8 or so further back to reach the shorter input.

the original Honcho 05-04-2013 08:58 PM

I Can't Wait To See This Write-Up!

4x4Dad 05-05-2013 06:55 PM


Originally Posted by pcoplin
The input shaft of the NP242 is shorter than the NP229. Make sure there is enough shaft engagement on the seal. If not, there are seals you can get that have a "snout" on them that will reach 3/8 or so further back to reach the shorter input.

Pulled the 229 this afternoon. Measured the depth of the input shafts of both. The 229 is three inches deep; the 242 is two and a half inches. I'm hoping that half inch won't be a real issue.

I don't think it will affect the mounting of the 242 since both transfer cases have the same measurement from the mounting flange of the case itself to the end of the input shaft (2 1/4"). If the tranny doesn't go all the way into the 229's input shaft, then I think it will be fine. I'll climb under there more tomorrow to see if there's going to be an issue here.

Carnuck 05-06-2013 10:44 PM

It's actually 15/16" difference, ergo the 1" spacer is needed going the other way.

pcoplin 05-06-2013 11:28 PM

Just lube the seal real good with Lubriplate (or something similar) and install, you'll see where the seal rides.

4x4Dad 05-06-2013 11:37 PM


Originally Posted by Carnuck
It's actually 15/16" difference, ergo the 1" spacer is needed going the other way.

I'm not following this. Can you explain this more?

4x4Dad 05-06-2013 11:53 PM

Here are pics of the 2 1/4" measurement I'm talking about.

They aren't the best pics, but the top one is the 242 and the bottom one the 229. Where does the 15/16" spacer you are talking about come into play?

Carnuck 05-07-2013 12:18 AM

If you put an AW4 in an FSJ and use the FSJ tcase, you need a 1" spacer. Going the other way you will have a matching gap between the trans output shaft and tcase input shaft bottom. (opposite of the way you are going) That means you will have 15/16" less engagement of the tcase input.

4x4Dad 05-12-2013 11:30 AM

Actually, that's not the case. I was worried about the same thing, so I measured when I pulled the 229. The output shaft for the TF727 is about 2" total (it doesn't even reach the edge of the transmission/transfer case mating surface), so it never even got close to bottoming out on the 229 input shaft. If anything, there will be less dead space inside the 242 input shaft than there is inside the 229. My guess is that they made the 229 input shaft long enough to accommodate a manual tranny output shaft, which is usually considerably longer than an auto output shaft.

4x4Dad 05-30-2013 04:25 PM

All done!

Running and working with the new-to-me NP242 and the Novak shifter.

I'll do a write up if there's any interest, but if not, I'm still a happy guy.

pcoplin 05-30-2013 05:02 PM

Nice! What did you end up doing?

Achilles 05-30-2013 05:15 PM

Do the write up please. Did you have to get a new rear drive shaft.

81cherokee laredo 05-30-2013 05:48 PM

I'm interested in a write up as well

Strode 05-30-2013 06:49 PM


Originally Posted by 81cherokee laredo
I'm interested in a write up as well

+1. And please be overly verbose. I hope you took pictures. I like to look at pictures.

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