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Jeep WJ 247-242HD Swap

326K views 865 replies 212 participants last post by  Brallen86 
#1 ·
1999-04 Jeep Grand Cherokee WJ Quadra-Trac/Quadra-Drive to Selec-Trac
(NP247 -> NP242HD)

Parts needed:

242HD (Only found in 2002-03 V8 grand Cherokees with Selec-Trac)
Matching drive shaft out of a 2002-03 V8 WJ with Selec-Trac
2 quarts of ATF +4

Optional:
Shifter assembly from a WJ with Selec-Trac
Mopar Part number: 52109671AB

If you have a 1999-2001 WJ, you might have a CV joint at the transfer case instead of a u-joint. In this case you will need to also find a donor shaft out of a 02+ V8 Grand Cherokee, or swap your old output to the new transfer case. The u-joint setup is much better and highly recommended however.

Tools needed:

1/4" Ratchet set
Short 1/4" extension
14mm or 9/16" deep socket
14mm or 9/16" regular socket
14mm or 9/16" wrench (ratcheting wrench highly recommended)
12mm regular socket
8mm regular socket
10mm Allen key
Pliers
Slotted screw driver
Lock-tite
Oil bucket
Floor jack
Jack stands (optional)

NP247 Removal:

1.) Depending on the rig you are working on you may or may not want to put it on jack stands.
a. If you have a 4" lift you will have enough room to work underneath on level ground, if not I would recommend putting it on stands.
b. Putting it on stands will also make it easier to take off the drive shafts.

2.) Once on stands and you have a transfer case skid plate, you will need to remove it. The stock one uses 3 bolts on the cross member, and 2 on the unibody.

3.) You will now need to drain the transfer case fluid.
a. Place your oil bucket below the drain plug.
b. Using a 10mm Allen key remove the fill and drain plugs.
c. Clean them and put them some where safe.

Diagram 1.1:


4.) While the transfer case drains remove the rear drive shaft.
a. Using a 1/4" ratchet, extension and 8mm socket, remove the bolts and the straps on the universal joint at the differential end of the rear drive shaft. Place them in a safe place.
b. Use a mallet if needed to knock the u-joint out of the yoke on the rear differential.
c. Once freed pull the drive shaft out of the slip yoke end of the transfer case. Place some where safe, though it will not be re-used.

5.) Remove the front drive shaft.
a. Using a 1/4" ratchet and 12mm regular socket remove the bolts from the front output of the transfer case to the drive shaft.
b. Use a mallet if needed to knock the u-joint out of the yoke at the transfer case.
c. Once free you can rest the drive shaft on the cross member as you will be re-using it.

Diagram 1.2:


6.) Lower the cross member so that you have room to work.
a. Use a floor jack to support the center of the cross member, jack it up so there is some pressure on the floor jack.
b. Remove the bolts.
- Use 15mm socket on the bolts.
- I have Claytons LA's, so I use 14mm sock and wrench.
- Place the bolts/nuts in a safe location.
c. Carefully Lower the cross member 1-2" ***Do not drop it lower***

Diagram 1.3:


7.) Remove shifter lever cable and bracket.
a. Pop the cable end off of the lever at the transfer case, you should be able to use your hands, if not use a slotted screw driver to pry it off.
b. Using 14mm socket remove 3 bolts located on driver side on the transmission. (Diagram 1.4)
c. Using a large wrench, put the bottom jaw on the bottom of the bracket, then the top jaw on the lip of the spring clamp holding the cable in the bracket. Apply pressure and it will pop right off. (Diagram 1.5)
d. Put the cable through the bottom hole, then put the spring clamp back on.

Diagram 1.4:


Diagram 1.5 - In original position:


Diagram 1.6 - In new position:


8.) Remove transfer case nuts.
a. Clean off the showing thread and soak in penetrating oil or WD40.
b. Use a combination of the 14mm deep socket, regular socket and ratcheting wrench.
c. The reason you will need the short sockets is there is not much room once you start to unthread the nuts on some of them. So you need to swap out or it will get stuck and you wont be able to get the wrench/socket out.
d. Be very patient as you will be doing a lot of 1 click ratcheting.
e. Clean the nuts thoroughly.

9.) Once the bolts are out, remove the transfer case. Having another person would be helpful, it weighs 80lbs so you should be able to manage it on your own. Place in a safe place.
a. Check your transmission output seal and replace if needed.
b. Check your breather tube to make sure its not split, if it is, cut off the split section and connect a new piece.

Diagram 1.7:


NP242HD Installation:

1.) Lift up and line up the 242HD with the bolt holes in the transmission mount.
a. You may need to rotate the input of the transfer case to line up with the transmission for it to slide in.
b. Once all the way in, it will be able to support its on weight.
c. Put the transfer case nuts back on, and use anti-seize.

2.) Once the transfer case is in position, bolt the shifter cable bracket back up.
a. Reinstall the 3 14mm bolts.
b. Clip the end of the cable onto the transfer case shifter, you may need to use a pair of pliers to pop it on.

3.) Bolt the cross member back up. Torque the 15mm bolts to 30-34ft lbs

4.) Reconnect the front drive shaft. Apply lock tite on the 12mm bolts then tighten.

5.) Connect the new rear drive shaft.
a. Slide the transfer case end into the slip yoke. You may need to rotate it so the splines match up.
b. Place the differential end back in the yoke, put the u-joint straps on, apply lock-tite to the 8mm bolt then tighten.

6.) Drain any remaining oil in the NP242HD.
a. Place your oil bucket below the drain plug.
b. Using a 10mm Allen key remove the fill and drain plugs.
c. Let what ever is in it drain out, then reinstall the drain plug.
d. Now use 2 quarts of ATF+4 to fill the transfer case.
e. Reinstall the fill plug

Diagram 1.8:



7.) Reinstall skid plate.

8.) Remove jack stands.

Notes:

I used a sticker instead of switching out the shifter assembly, since you can use your old one without a problem.

Expect to spend approximately 4-8 hrs to complete this swap.

***I just noticed when I did this write up it was before I started working with Carolina Driveline - I highly recommend them, I ended up using them and replacing the junkyard shaft when I went from 5" to 8" of lift.
 
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#3 ·
did you take it for a test drive to see if this helped with your vibes??
 
#5 ·
Nice Job Nick, hope you don't mind, but I added your write-up to the FAQ's :thumbsup:
 
#12 ·
Yeah just very minor rear vibes, front ones are completely gone.

The aussie behaves much better and doesn't bind up now even if its in 2wd or FT 4wd, FT 4wd it is best.

We'll see about selling it I may not have a choice...I'd like to keep it.
 
#17 ·
Excellent writeup with great pics. Super job Nick.

my 247 got broken and i would like to swap mine.
but i have few questions.
how much did you spend? what is your gas mileage now?
and if the 242hd is too expensive is there any other i could use for my truck??

99 jeep GC Ltd 4.0l L6

thank you in advance.
 
#18 ·
Since you have a I6 you don't need a 242HD, in fact if you got a 242HD you would have to swap your input from your 247 over in order to mate it to your transmission.

Go on car-part.com and look for a selec-trac transfercase for a I6, and you should even be able to use your existing drive shaft with that.

If you don't mind losing full-time 4wd and want something tougher you can bolt in a transfercase from a Rubicon.

Here's a list of transfercases, anything that is 23 spline and .840" exposed input will swap directly into your transmission (I think...you'd have to look at the actual input I know some have different colars so you need to be aware of that)

http://www.drivetrain.com/transfercaseappjeep.html#GRAND CHEROKEE

And a much bigger list:

http://www.drivetrain.com/transfercaseapp.html

Lots of a great info in those links, those should really be in the faq, I guess they are now.
 
#26 ·
Since you have a I6 you don't need a 242HD, in fact if you got a 242HD you would have to swap your input from your 247 over in order to mate it to your transmission.

Go on car-part.com and look for a selec-trac transfercase for a I6, and you should even be able to use your existing drive shaft with that.
be careful on car-part.com when looking up '99 WJ transfer cases - for that year they dont specify if its from a V8 or I6 so you may get the wrong one unless you tell them you have a 2000 or something.

I got a '99 I6 t-case for my '99 V8, installed it and the input shaft was too short so I had to drive all the way back to the yard. Got an '03 HD at another yard.
 
#24 ·
$225 for mine, + $100 for the driveshaft.

My mileage is about 15-17 but I have 4.10's and 33's.
 
#25 ·
you made it look way too easy i think i am going to have to give it a try...:thumbsup:
 
#28 ·
You're not running a SYE at 8" ??

I wouldn't get the 242HD for your application because there is no SYE for it, though you could get something custom made...you'd be better off with a 231HD and a SYE. (though you wont get full time 4wd then)
 
#30 ·
great write up..just picked up a 242hd today..does the crossmember or mounting for the t-case change any from the 247 to the 242 or does all that bolt right up?
 
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