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Np242j HnT kit

outracing

NAXJA Forum User
Location
ohio
Hello everyone, I just purchased a 1998 Jeep Cherokee Limited. It is a very nice vehicle with a hundred thousand miles. I would like to lift it 4 and 1/2 inches. With that size lift, I know that I will need to lengthen my drive shaft. My issue is, when I look at full SYE kits or HnT kits there seems to not be very much available for the np242j that is installed in my Cherokee. I would like to find a complete kit with everything I need to make the job is easy as possible. I would like one with the new yoke, any seals, all of the guides, drill bits, as well as the tap and bolt. Is there a company that has this available for the 242? I see lots of them available for the 231, are these basically interchangeable? Thank you for all of your help!
 
I don't know about the later rigs, but my 92 is sitting at around 4.5 inches, and I'm still running stock driveshafts front and rear (including the original fixed-length, slip yoke rear) without issues.

Now, I'll concede that I am running with a one-inch tcase drop - was put in back when I did the original 2 inch lift years ago to address driveline vibes, but I've never re-encountered vibes as I went from 2 inches to 3, to 4.5.

Point is, you may not need longer shafts at all.
 
I don't know about the later rigs, but my 92 is sitting at around 4.5 inches, and I'm still running stock driveshafts front and rear (including the original fixed-length, slip yoke rear) without issues.

Now, I'll concede that I am running with a one-inch tcase drop - was put in back when I did the original 2 inch lift years ago to address driveline vibes, but I've never re-encountered vibes as I went from 2 inches to 3, to 4.5.

Point is, you may not need longer shafts at all.



I had a 98 before with an np231 transfer case. It only had a 3-inch lift, but I kept managing to break the yoke on the rear drive shaft at the axle side. I ended up installing degree shims as well which helped with the issue, but it still had some massive vibration on the highway.
 
..... looking for a hack and tap kit

Iron Rock Off Road.


One of the guys in my local Jeep club didn't think he needed an SYE, until he did. He spent the weekend waiting for a tow truck, and calling junkyards. We spent the weekend playing in the woods.


YMMV.



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I’m running the IRO hack and tap. I like it just fine, but if I had it to do over again I would not have spent the extra $30 on their drilling jig for reasons stated here:

I recently installed an IRO hack 'n tap yoke onto my NP242 TC. It was a straight-forward and fun little project. I haven't had a chance to test for vibrations yet because I've got to deal with a couple of unrelated issues before I can drive the Jeep. But I expect no problems.

I did make one observation about IRO's kit that I will pass on, along with a recommendation born of my experience for anyone considering this modification.

The installation instructions call for drilling a 1/4 inch pilot hole into the end of the output shaft (after cutting), followed by a 5/16 inch hole to be tapped. Drilling a pilot hole makes good sense of course, considering that the shaft is hardened steel. To ensure a straight and centered hole, IRO sells a drilling jig for $30, which I bought. Oddly though, the alignment hole in the jig is 5/16 of an inch, which makes it fairly useless for aligning the pilot hole. And once the pilot hole is drilled, the path of the 5/16 drill bit is determined and the jig becomes pointless. I overcame these issues and managed to get a perfectly centered and straight hole, but I will not credit iRO's jig with the success of the process.

My recommendation to anyone considering this modification is save $30 and do not buy the jig. It is not as helpful as it should be, in my opinion. With a little ingenuity you should be able to make a better jig yourself for a 1/4 inch pilot hole.

Here are some pictures to show off my handwork:

C9C2C91E-1EBF-4A10-9E96-EC34360A6CDB_zpshdmaygyl.jpg


AD69373F-5551-4084-BF4E-B7E29B6D52F0_zpskbrbnb2x.jpg

If you go back and read that whole thread, though, you’ll see that a couple of people disagreed with me about the jig while never actually refuting the point I made.

Here’s the thread:

https://www.naxja.org/forum/newreply.php?do=newreply&p=246251088

For convenience, here’s a link to the IRO page:

https://www.ironrockoffroad.com/product/hack-n-tap-slip-yoke-eliminator-kit.html
 
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I’m running the IRO hack and tap. I like it just fine, but if I had it to do over again I would not have spent the extra $30 on their drilling jig for reasons stated here:

I've used the IRO hack and tap, good product and works well on my 242.

I found the jig to be helpful. You are correct about it being 5/16", and IRO suggesting a 1/4" pilot hole. I thought the same as you did.

I started with a 5/16" bit just a little way to get my center point. Once that was established, I was able to hold the 1/4" drill pretty centered with the aid of the jig. I used a buddy's lift, though, so it was much easier to guide the drill.

I ended up selling it to another Jeeper for $20.00. Got lucky, but worked out well for me, would buy it again. YMMV.
 
I did the HnT on a '98 with the 8-1/4 rear end. I was at or still at 4.5" lift. It was actually higher, probably 6" before it settled. I had to cut to the minimum of 1-1/8" spline length. I used a front drive shaft from an Auto. There are instruction with the IRO Kit. I did have to cut some of the Yoke OD off.
I did get the drill jig. I can't remember if I used a long length center drill in the jig or not. Use a new and high quality tap. Mine was a Np 231.
 
I did the HnT on a '98 with the 8-1/4 rear end. I was at or still at 4.5" lift. It was actually higher, probably 6" before it settled. I had to cut to the minimum of 1-1/8" spline length. I used a front drive shaft from an Auto. There are instruction with the IRO Kit. I did have to cut some of the Yoke OD off.
I did get the drill jig. I can't remember if I used a long length center drill in the jig or not. Use a new and high quality tap. Mine was a Np 231.


Are the 231 and 242 HnT kits the same?
 
Are the 231 and 242 HnT kits the same?

Yes, mostly.

If the t-case has the 1996-2001 external splined output shaft the H&T is the same, 231 vs 242. If the t-case has the 1995 and older internal output shaft and requires the add-on seal housing with the SYE install you should confirm that the seal housing works with a 242.
 
Yes, mostly.

If the t-case has the 1996-2001 external splined output shaft the H&T is the same, 231 vs 242. If the t-case has the 1995 and older internal output shaft and requires the add-on seal housing with the SYE install you should confirm that the seal housing works with a 242.

That will be most helpful! Thank you!
 
I don't know about the later rigs, but my 92 is sitting at around 4.5 inches, and I'm still running stock driveshafts front and rear (including the original fixed-length, slip yoke rear) without issues.

Now, I'll concede that I am running with a one-inch tcase drop - was put in back when I did the original 2 inch lift years ago to address driveline vibes, but I've never re-encountered vibes as I went from 2 inches to 3, to 4.5.

Point is, you may not need longer shafts at all.

I am still pretty green, but I have had the exact experience on my '91 242. On/off road, full flex, no vibrations whatsoever or any issues as of yet..
 
Hack and tap 100 bucks.

Real live slip yoke eliminator with 32 spline out put 200.

Seems a simple decision can be made to spend more and get more.
While drive lines are out inspect or just replace ujoints they may also be a source of the vibration
 
Looks like I'm wrong. There are 242 she out there but they cost substantially more than the 231 sye kits
 
Itl hold up till it doesnt guess the same could be true of the sye.
Sometimes the best tuffest parts still break at the very worst possible time.
 
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