NP242 Hack N' Tap Question.

Here's my deal;

I have a 1999 Jeep Cherokee. 4.0/AW4/242 case.

I just bought another NP242 with a SYE on it. (Not sure what kind of SYE it is.)

I want to put the SYE from the case i just bought onto my current jeep. Is this possible? What would i need to do? Would it be easier to just swap the entire case into my jeep?

Pictures are of the case and SYE i just bought.

Unless you feel comfortable and want to spend the time pulling the t-cases apart. I would just swap it, especially if the T-case is good. I personally dislike the RE flange setup. But you can always swap in a yoke. I have a re flange if you want to buy it. Ha.

Johnnie Walker said:

Unless you feel comfortable and want to spend the time pulling the t-cases apart. I would just swap it, especially if the T-case is good. I personally dislike the RE flange setup. But you can always swap in a yoke. I have a re flange if you want to buy it. Ha.

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Would you mind elaborating a little bit? I'm not quite sure i get you.

Are you saying i'd have to take both cases apart? He said the T-case is good (member on another forum with a bajillion posts) so i trust his word. I've never swapped a T-case in my life, so i have no clue what that entails.

If i were to "swap in a yoke" as you've said i could what would that do? Would that make me not have to take the cases apart? I know literally nothing about SYEs except that i need one. Haha.


I have another question on top of this. I unbolted the shaft from the case and began wire-wheeling it to clean it up. I went to pull the Unis from the double-cardian side of the shaft (i've never done this before) and once i got two caps off i discvoered there is some sort of pivot thing holding it together. How do i get both of these unis out? Picture shows where i'm currently at.

Keep working on the same joint. Rotate the shaft 90* and do the same thing to remove the last 2 caps. It can be a bit of a PITA but is doable with some patience. The flange end will have to pivot as you remove the joint you are currently working on.

Edit: in that pivot joint there is a small spring and some needles. They should be retained by the grease in the joint but be sure not to lose them.

Well got everything apart. I'm pretty sure i ... lost the spring and needles. Used a cutting wheel to get the last uni out and the entire shaft fell on the ground. Don't see a spring anywhere but i'll go look for it in a minute here.

Are these parts replaceable? (will a local parts store carry them, or am i doomed?)

Not sure if i found something new or everyone just assumes everyone does it, but i found an easy way to make a vice a press. Pressed the last uni out with ease once i figured this out. (no more beating on a socket with a hammer.) Look at that damn socket to the right of this picture. Haha.

Anyways, now my only question is;

What is the best way to get this Hack N' Tap into my jeep?

Yes the centering ball is avalible aftermarket. Great job on the vice press. Any time you don't have to beat a joint in or out is a good day.

GREASYHANDS said:

Yes the centering ball is avalible aftermarket. Great job on the vice press. Any time you don't have to beat a joint in or out is a good day.

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Would you happen to have a link for this? I'm not sure if they're special or how to order them. Does the front XJ shaft have some name to buy these for, or do all shafts have the same centering ball?

Thank you. Hopefully someone else can use my vice-press idea as it works lovely.

Just need to figure out how to get this HNT into my Jeep now and i'll be a happy boy. arty:

Install the whole Tcase, it just bolts on. You should have left the drive shaft alone, now you are probably going to have to replace both the double cardan u-joints and the centering ball.

I've heard the top two bolts are a real PITA to get out. Any easy ways to get the transfer case out? Also do you know if they're e12s or e14s? I think i remember reading somewhere that they weren't just standard bolts and once they're out replace them with regular bolts. How do i know if this case will bolt up to my jeep? Case is out of a 93.

Are the double carden joints special ones? Also where do i get the centering ball? You're right. I should of left it alone but could of, should of, would of. Can't go back now.

What if i just remove the 4 bolts around the SYE and take that piece of the transfer case off, and then unbolt that from my jeep and swap them? Or it doesn't work like that?

Kingkong0192 said:

I've heard the top two bolts are a real PITA to get out. Any easy ways to get the transfer case out? Also do you know if they're e12s or e14s? I think i remember reading somewhere that they weren't just standard bolts and once they're out replace them with regular bolts. How do i know if this case will bolt up to my jeep? Case is out of a 93.

Are the double carden joints special ones? Also where do i get the centering ball? You're right. I should of left it alone but could of, should of, would of. Can't go back now.

What if i just remove the 4 bolts around the SYE and take that piece of the transfer case off, and then unbolt that from my jeep and swap them? Or it doesn't work like that?

Click to expand...

IIRC, the t-case just uses standard nuts all around. It's the trans that has the E12 torx at the top ( i usually just replace them with correct length hex bolts).
If you have HO, then you are set. HO vintage trans all use 23-spline. Depending on your year (forget if you said it already) You may have to swap sensors between the cases.
The output shaft of a SYE/Hack n Tap case is cut shorter than the stock shaft. So it is not just a "straight swap". You would have to cut down your output shaft, drill and tap it. OR, pull both cases apart and swap the shaft over. Lots of unnecessary work.
As far as flange vs yoke, you would just have to find a correct-spline yoke to swap/bolt in. Some say that the front and rear outputs have the same dia/spline shafts so in theory a stock front yoke should "bolt in" Otherwise, find a correct length yoke, or one that fits the splines and cut it down to size.
I, myself, am going to try and swap a stock yoke in place of the flange I have on my 242.

Overall, much simpler to just keep the t-case intact and swap it. I want to use the yoke, vs flange for 2 reasons. 1) I dont have a flange adapter for driveshaft. 2) I would like to be able to use the same driveshaft front/rear, so mostly would only have to carry one spare that works for either.

Alright thank you. That sums it up nicely.

Just a few more questions.

1. Do you know where i can buy a new centering ball?
2. Do you know which U-Joints are on this shaft? I need to replace all 3 of them and am not sure what kind of U-Joints to replace them with.
3. I always get these mixed up. What is a flange, and what is a yoke? Is the flange the thing my shaft bolts to on the hack and tap and the yoke is the thing the u-joint goes into on the rear axle?

Yes. My jeep is a H.O. It's a 99. Donor jeep is a 93. (Not sure if H.O). Would i have to swap sensors?

Once i get the front shaft rebuilt i'll swap the cases. Have to put a Durango Steering box in the jeep tomorrow.

1. - Been years since I rebuilt one, no idea.
2. - I would go with some quality spicer joints. I am sure someone knows the correct PN.
3. - If you look at the pictures in your OP the HnT uses a flange, which is circular, hence why the flange adapter for the driveshaft is necessary. On your axles (unless you have an 8.8) and the front output on the t-case have yokes. Sorry, if my explanation is not technical enough.. already down several beers today.

91 was the start of HO, so both HO, both 23-spline, but later models, I believe, used different sensors. easy enough to swap tho.

Thank you.

Just bought 3 new Moog ujoints and the centering ball off rockauto. Was like $65 for everything.

Once that is rebuilt it'll go on the jeep. Ill search when I get home but do you know off the top of your head how to swap sensors? Is soldering required?

I believe that they are the "screw-in" type. Should be able to unscrew them and swap. You can look at the one you have out. Sensors should at least be similar, wiring changed in the later years so it's better to take just a few minutes to swap them while everything is out.