Coachgeo
TJ Enthusiast
is that denoted as a WJ? apologize don't know my Cherokee's. What about a 2002? There is one near me apparently.
is that denoted as a WJ? apologize don't know my Cherokee's. What about a 2002? There is one near me apparently.
That's right, thanks @Wildman . The WJ and ZJ, which also came with an NP242, would not be a plug-and-play install in a TJ due to the lack of a hole for a speedo gear in the transfer case; They track speed in other forms.
While you could potentially adapt for different forms of speed tracking, it's much simpler to find an 97-01 XJ (Cherokee) with a fully compatible np242.
While you could potentially adapt for different forms of speed tracking, it's much simpler to find an 97-01 XJ (Cherokee) with a fully compatible np242.
I'm kicking myself for selling the 242's I had when I sold my daughters other Jeep. I should see if the buyer still has them and would want to sell them back to me.
I'd forgotten about the GC's not having a speedo output like the JK's.
Coachgeo
TJ Enthusiast
don't care so much about speedo... app's with GPS speedometer are free out there. Also, inexpensive digital gps speedos are out there too. Don't need speedo input to any computers if that is a Jeep thing... engine in TJ is all mechanical (MB diesel). Though it would be great to keep gauge cluster stockish looking its not high on priority list.
My concern is 95% being able to matee to 5speed NV3550. Thus thinking I need long input shaft on Tcase w/23spline. Lonrg also likely better since the diesel engine is little torquey. Not a V8 but think little more than the Jeep Inline 6. All am finding is short input shafts.
Clocking has been mentioned in other places.... is this true?? you have to re-clock or if not that drop skid plate? IF drop skid plate do you space the tcase/tranny mount up as much as you drop plate down? (not counting drop for driveshaft angle.. would hack-n-tap for that.
Last edited:
If you don't mind finding a different speedo solution, then it is a viable swap.
The only concern with compatibility aside from that is if it is an np242HD (mated to the V8 models) or an np242j (mated to the 4.0L models). Although both were offered on the WJ, you cannot narrow down the input shaft/spline count unless you figure out which engine it was used for. Also, make sure it isn't a np249 which was a full-time 4wd transfer case (non-2wd) also offered in the WJ.
So if you can figure out what year WJ with what transmission it came out of, you can narrow down whether it will fit or not. For reference, my transfer case was originally out of an '00 XJ with an AW-4 automatic transmission, and it went into my TJ with an nv3550; it had a short input shaft and was a 23 spline.
So if it came out of a 4.0L it will work, but it will not work out of a v8 model. Specifically, I believe your transmission (nv3550) will work with both a 23-spline short-input and a 23-spline medium-input, but it will not work with a long-input shaft because it will supposedly destroy the transmission. If it is a np242HD it will have a long input shaft, and therefore will not work because it can destroy your transmission.
Also, it must be from a '95 or newer 4.0L WJ because the spline count & gear tooth design changed.
Last edited:
You should be able to install your np231 input shaft into the np242. Problem solved. The gear design thing is a planetary issue, internal to the tcase.it isn't a transmission compatibility problem. So long as the input being swapped in is of the same old or new style it isn't an issue. A long input won't destroy anything so long as it doesn't bottom out before the tcase is flush with the trans.i would look at trimming the input before swapping it out.
The spline count of the transmission output isn't motor specific. Its year model and transmission specific. Aw4 uses a couple different splines.
Last edited:
The transmission tailhousing does the clocking,specifically tj and cherokee are different.auto or manual is irrelevant. Use the wrong one and it will indeed be a problem when it is banging off the skid plate
That's a good point! By swapping the input shafts, you would be solving the majority of the compatibility issues.
It is a more involved procedure since you have to take the case apart, but if you think you'll see significant wheeling, then you could get a rebuild kit and do it while you're in there.
Like I said before, it just needs to be a '95 or newer WJ since they switched from 21- to 23- spline and the newer gear tooth design.
Thanks for clarifying, I wasn't 100% sure of my info but since we have the same transmission I knew the clocking wouldn't be an issue for him specifically.
Coachgeo
TJ Enthusiast
getting an 2003 NP242 WJ off an 4.0 automatic Grand Cherekee tomorrow. Won't be doing serious wheeling for a while. What is considered short medium etc for input . my present 231 has around 1 3/8 inch long input shaft sticking out past the ring on the bolt on collar at front of 231.
Coachgeo
TJ Enthusiast
thanks but does not help. (or am too dumb to understand it.... which is possible) The 2003 Grand cherokee transmission(s) are not on the chart(s) in document (42RE , 45RFE and 545RFE) so that does not help... It does mention the 42RE at the end.... something about about the input shaft pilot tip... but no mention what, if any correlation that has to any possible swaps. Also no actual measurements of short/medium/long are there to help one truly clarify
The long shafts protrude 2.1" from the front mounting face of the transfer case. The short version protrudes 1.2". You should be careful when swapping any of these gears due to different bearing widths and gear teeth. The following chart shows how to determine which input gear you might have by transmission. It is always recommended to verify first hand if possible.
Coachgeo
TJ Enthusiast
unfortunately this is still not much help.... my guess is the 5speed and 231 is original 2002 on the 2002 TJ still.. but no way to verify. AKA- how much this rig got mix matched before I purchased it I don't know. Lot of customizing/hacking happened before I bought it. Trans for sure NV3550 (actually says NVG 3550 if not mistaken). 231 on it may have come with that trans.... may have been swapped in. Does not have a Jeep engine either. Guess I'll just have to call Novak with my serial numbers from each Tcase and trans to see if they can tell me what is what about them and if the input can be swapped over.
Much thanks
Not sure what more information you are needing. You say you have about 1.3" sticking out now which would mean you have a short input gear. Once you have the 242 t-case you measure it and go from there. As has been suggested before you can always swap input gears if you want.
Novak might be able to help you more.
Coachgeo
TJ Enthusiast
info needed.. prior to disassembly (so it is not waste of time) Is the input gear "completely" the same from bearing size to gear cut between the two or do I have to order one.. if so which one. If I was to try to get used or new what one what would I look for (years, vehicle from, type trans and/or T-case part # etc)
Novak might be able to answer these questions and they may not. Obviously when doing custom things there are times the only way to verify things are by disassembly. If I still had my 242 t-cases here I'd try to help out but I sold them.
the nvg3550 is the same transmission I have; it is referred to as the nv3550 interchangeably on the forums since it was the naming convention used in the gm truck applications it was derived from. (novak)
Based on what I have read, you should realistically only have issues if you have a transmission that was originally mated to a short input gear transfer case, which the nvg3550 did not in any application (only used in XJs/TJs)
So ultimately I think there should not be an issue given your transmission and the vehicle year/make/model the transfer case was sourced from.
Based on what I have read, you should realistically only have issues if you have a transmission that was originally mated to a short input gear transfer case, which the nvg3550 did not in any application (only used in XJs/TJs)
So ultimately I think there should not be an issue given your transmission and the vehicle year/make/model the transfer case was sourced from.
Coachgeo
TJ Enthusiast